On Thu, Jan 24, 2013 at 10:20 AM, Daniel Vetter daniel.vetter@ffwll.ch wrote:

Omapdrm doesn't do anything nefarious with crtc load detection or has any shared resources, so this is enough. We also need to adjust the WARN_ON.

looks good, after I double checked the locking in setplane. In case I didn't send this earlier,

Reviewed-by: Rob Clark rob@ti.com

Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch

drivers/staging/omapdrm/omap_crtc.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/omapdrm/omap_crtc.c b/drivers/staging/omapdrm/omap_crtc.c index 510942e..fb5d722 100644 --- a/drivers/staging/omapdrm/omap_crtc.c +++ b/drivers/staging/omapdrm/omap_crtc.c @@ -274,17 +274,16 @@ static void page_flip_worker(struct work_struct *work) struct omap_crtc *omap_crtc = container_of(work, struct omap_crtc, page_flip_work); struct drm_crtc *crtc = &omap_crtc->base;

•   struct drm_device *dev = crtc->dev;
    struct drm_display_mode *mode = &crtc->mode;
    struct drm_gem_object *bo;
  
  

•   drm_modeset_lock_all(dev);
  

•   mutex_lock(&crtc->mutex);
    omap_plane_mode_set(omap_crtc->plane, crtc, crtc->fb,
                    0, 0, mode->hdisplay, mode->vdisplay,
                    crtc->x << 16, crtc->y << 16,
                    mode->hdisplay << 16, mode->vdisplay << 16,
                    vblank_cb, crtc);
  

•   drm_modeset_unlock_all(dev);
  

•   mutex_unlock(&crtc->mutex);
  
    bo = omap_framebuffer_bo(crtc->fb, 0);
    drm_gem_object_unreference_unlocked(bo);
  

@@ -417,7 +416,7 @@ static void apply_worker(struct work_struct *work) * the callbacks and list modification all serialized * with respect to modesetting ioctls from userspace. */

•   drm_modeset_lock_all(dev);
  

•   mutex_lock(&crtc->mutex);
    dispc_runtime_get();
  
    /*
  

@@ -462,16 +461,15 @@ static void apply_worker(struct work_struct *work)

out: dispc_runtime_put();

•   drm_modeset_unlock_all(dev);
  

•   mutex_unlock(&crtc->mutex);
  

}

int omap_crtc_apply(struct drm_crtc *crtc, struct omap_drm_apply *apply) { struct omap_crtc *omap_crtc = to_omap_crtc(crtc);

•   struct drm_device *dev = crtc->dev;
  
  

•   WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
  

•   WARN_ON(!mutex_is_locked(&crtc->mutex));
  
    /* no need to queue it again if it is already queued: */
    if (apply->queued)
  

-- 1.7.10.4

---

dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel

On Thu, Jan 24, 2013 at 10:20 AM, Daniel Vetter daniel.vetter@ffwll.ch wrote:

We don't need to hold onto mode_config.mutex any more to keep the fb objects around. And locking dev->struct_mutex is also not required, since omap_gem_describe only reads data anyway. And for a debug interface it's better to grab fewer locks in case the driver is deadlocked already ...

The only thing we need is to hold onto mode_config.fb_lock to ensure the user-created fbs don't disappear. The fbcon fb doesn't need any protection, since it lives as long as the driver (and so the debugfs files) itself. And if the teardown/setup isn't following the right sequence grabbing locks won't prevent a NULL deref on priv->fbdev if the fb is not yet (or no longer) there.

agreed

Reviewed-by: Rob Clark rob@ti.com

Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch

drivers/staging/omapdrm/omap_debugfs.c | 14 -------------- 1 file changed, 14 deletions(-)

diff --git a/drivers/staging/omapdrm/omap_debugfs.c b/drivers/staging/omapdrm/omap_debugfs.c index e95540b..2bf0664 100644 --- a/drivers/staging/omapdrm/omap_debugfs.c +++ b/drivers/staging/omapdrm/omap_debugfs.c @@ -57,17 +57,6 @@ static int fb_show(struct seq_file *m, void *arg) struct drm_device *dev = node->minor->dev; struct omap_drm_private *priv = dev->dev_private; struct drm_framebuffer *fb;

•   int ret;
  

•   ret = mutex_lock_interruptible(&dev->mode_config.mutex);
  

•   if (ret)
  

•           return ret;
  

•   ret = mutex_lock_interruptible(&dev->struct_mutex);
  

•   if (ret) {
  

•           mutex_unlock(&dev->mode_config.mutex);
  

•           return ret;
  

•   }
  
    seq_printf(m, "fbcon ");
    omap_framebuffer_describe(priv->fbdev->fb, m);
  

@@ -82,9 +71,6 @@ static int fb_show(struct seq_file *m, void *arg) } mutex_unlock(&dev->mode_config.fb_lock);

•   mutex_unlock(&dev->struct_mutex);
  

•   mutex_unlock(&dev->mode_config.mutex);
  

•   return 0;
  

}

-- 1.7.10.4

---

dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel

On Thu, Jan 24, 2013 at 10:20 AM, Daniel Vetter daniel.vetter@ffwll.ch wrote:

... it's required. Fix up exynos and the cma helper, and add a corresponding WARN_ON to drm_fb_helper_restore_fbdev_mode.

Note that tegra calls the fbdev cma helper restore function also from it's driver-load callback. Which is a bit against current practice, since usually the call is only from ->lastclose, and initial setup is done by drm_fb_helper_initial_config.

Also add the relevant drm DocBook entry.

Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch

With the actual addition of the promised WARN_ON,

Reviewed-by: Rob Clark robdclark@gmail.com

---

drivers/gpu/drm/drm_fb_cma_helper.c | 2 ++ drivers/gpu/drm/drm_fb_helper.c | 8 ++++++++ drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 2 ++ 3 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c index 3742bc9..1b6ba2d 100644 --- a/drivers/gpu/drm/drm_fb_cma_helper.c +++ b/drivers/gpu/drm/drm_fb_cma_helper.c @@ -389,8 +389,10 @@ EXPORT_SYMBOL_GPL(drm_fbdev_cma_fini); */ void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma) {

•   drm_modeset_lock_all(dev);
    if (fbdev_cma)
            drm_fb_helper_restore_fbdev_mode(&fbdev_cma->fb_helper);
  

•   drm_modeset_unlock_all(dev);
  

} EXPORT_SYMBOL_GPL(drm_fbdev_cma_restore_mode);

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 0c6e25e..0439cb0 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -239,6 +239,14 @@ int drm_fb_helper_debug_leave(struct fb_info *info) } EXPORT_SYMBOL(drm_fb_helper_debug_leave);

+/**

• • drm_fb_helper_restore_fbdev_mode - restore fbdev configuration
• • @fb_helper: fbcon to restore
• • This should be called from driver's drm->lastclose callback when implementing
• • an fbcon on top of kms using this helper. This ensures that the user isn't
• • greeted with a black screen when e.g. X dies.
• */

bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper) { bool error = false; diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c index 90d335c..086d0f7 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c +++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c @@ -376,5 +376,7 @@ void exynos_drm_fbdev_restore_mode(struct drm_device *dev) if (!private || !private->fb_helper) return;

•   drm_modeset_lock_all(dev);
    drm_fb_helper_restore_fbdev_mode(private->fb_helper);
  

•   drm_modeset_unlock_all(dev);
  

}

1.7.10.4

---

dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel

On Thu, Jan 24, 2013 at 10:20 AM, Daniel Vetter daniel.vetter@ffwll.ch wrote:

It's only used internally for the sysrq and panic handlers provided by the drm fb helper implementation. Hence just inline it, kill the export and remove the confusing kerneldoc. Driver's are supposed to call drm_fb_helper_restore_fbdev_mode on lastclose.

Note that locking is totally fubar - the sysrq case doesn't take any locks at all. The panic handler probably shouldn't take any locks since it'll only make things worse. Otoh it's probably better to switch things over to the atomic modeset callbacks (and disable the panic handler for those drivers which don't implement it).

But that's both better done in separate patches.

Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch

Reviewed-by: Rob Clark robdclark@gmail.com

---

drivers/gpu/drm/drm_fb_helper.c | 23 ++++++++--------------- include/drm/drm_fb_helper.h | 1 - 2 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 0439cb0..6d689f2 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -261,6 +261,10 @@ bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper) } EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode);

+/*

• • restore fbcon display for all kms driver's using this helper, used for sysrq
• • and panic handling.
• */

static bool drm_fb_helper_force_kernel_mode(void) { bool ret, error = false; @@ -299,20 +303,6 @@ static struct notifier_block paniced = { .notifier_call = drm_fb_helper_panic, };

-/**

• • drm_fb_helper_restore - restore the framebuffer console (kernel) config
• • Restore's the kernel's fbcon mode, used for lastclose & panic paths.
• */

-void drm_fb_helper_restore(void) -{

•   bool ret;
  

•   ret = drm_fb_helper_force_kernel_mode();
  

•   if (ret == true)
  

•           DRM_ERROR("Failed to restore crtc configuration\n");
  

-} -EXPORT_SYMBOL(drm_fb_helper_restore);

static bool drm_fb_helper_is_bound(struct drm_fb_helper *fb_helper) { struct drm_device *dev = fb_helper->dev; @@ -334,7 +324,10 @@ static bool drm_fb_helper_is_bound(struct drm_fb_helper *fb_helper) #ifdef CONFIG_MAGIC_SYSRQ static void drm_fb_helper_restore_work_fn(struct work_struct *ignored) {

•   drm_fb_helper_restore();
  

•   bool ret;
  

•   ret = drm_fb_helper_force_kernel_mode();
  

•   if (ret == true)
  

•           DRM_ERROR("Failed to restore crtc configuration\n");
  

} static DECLARE_WORK(drm_fb_helper_restore_work, drm_fb_helper_restore_work_fn);

diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h index 5120b01..ba32505 100644 --- a/include/drm/drm_fb_helper.h +++ b/include/drm/drm_fb_helper.h @@ -103,7 +103,6 @@ int drm_fb_helper_setcolreg(unsigned regno, struct fb_info *info);

bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper); -void drm_fb_helper_restore(void); void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helper, uint32_t fb_width, uint32_t fb_height); void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch, -- 1.7.10.4

---

dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel

On Thu, Jan 24, 2013 at 10:20 AM, Daniel Vetter daniel.vetter@ffwll.ch wrote:

It doesn't even show up in any header files and only used iternally. Originally it was (ab)used to restore the fbcon on lastclose, but that died with

commit e8e7a2b8ccfdae0d4cb6bd25824bbedcd42da316 Author: Dave Airlie airlied@redhat.com Date: Thu Apr 21 22:18:32 2011 +0100

drm/i915: restore only the mode of this driver on lastclose (v2)

Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch

Reviewed-by: Rob Clark robdclark@gmail.com

---

drivers/gpu/drm/drm_fb_helper.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 6d689f2..ce816a5 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -284,7 +284,7 @@ static bool drm_fb_helper_force_kernel_mode(void) return error; }

-int drm_fb_helper_panic(struct notifier_block *n, unsigned long ununsed, +static int drm_fb_helper_panic(struct notifier_block *n, unsigned long ununsed, void *panic_str) { /* @@ -297,7 +297,6 @@ int drm_fb_helper_panic(struct notifier_block *n, unsigned long ununsed, pr_err("panic occurred, switching back to text console\n"); return drm_fb_helper_force_kernel_mode(); } -EXPORT_SYMBOL(drm_fb_helper_panic);

static struct notifier_block paniced = { .notifier_call = drm_fb_helper_panic, -- 1.7.10.4

---

dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel

This should be done in the drivers for two reasons: - it gets in the way of fastboot efforts - it links the fb helpers with the crtc helpers instead of going through the real interface vfuncs, forcing i915 to fake all the ->disable callbacks used by the crtc helper to avoid ugly Oopsen

v2: Resolve conflicts since drivers still call drm_fb_helper_single_add_all_connectors.

Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch --- drivers/gpu/drm/ast/ast_fb.c | 5 +++++ drivers/gpu/drm/cirrus/cirrus_fbdev.c | 4 ++++ drivers/gpu/drm/drm_fb_cma_helper.c | 3 +++ drivers/gpu/drm/drm_fb_helper.c | 3 --- drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 3 +++ drivers/gpu/drm/gma500/framebuffer.c | 4 ++++ drivers/gpu/drm/i915/intel_fb.c | 3 +++ drivers/gpu/drm/mgag200/mgag200_fb.c | 5 +++++ drivers/gpu/drm/nouveau/nouveau_fbcon.c | 3 +++ drivers/gpu/drm/radeon/radeon_fb.c | 4 ++++ drivers/gpu/drm/udl/udl_fb.c | 4 ++++ drivers/staging/omapdrm/omap_fbdev.c | 4 ++++ 12 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/ast/ast_fb.c b/drivers/gpu/drm/ast/ast_fb.c index 3e6584b..81763ca 100644 --- a/drivers/gpu/drm/ast/ast_fb.c +++ b/drivers/gpu/drm/ast/ast_fb.c @@ -40,6 +40,7 @@ #include <drm/drmP.h> #include <drm/drm_crtc.h> #include <drm/drm_fb_helper.h> +#include <drm/drm_crtc_helper.h> #include "ast_drv.h"

static void ast_dirty_update(struct ast_fbdev *afbdev, @@ -314,6 +315,10 @@ int ast_fbdev_init(struct drm_device *dev) }

drm_fb_helper_single_add_all_connectors(&afbdev->helper); + + /* disable all the possible outputs/crtcs before entering KMS mode */ + drm_helper_disable_unused_functions(dev); + drm_fb_helper_initial_config(&afbdev->helper, 32); return 0; } diff --git a/drivers/gpu/drm/cirrus/cirrus_fbdev.c b/drivers/gpu/drm/cirrus/cirrus_fbdev.c index 3daea0f..b96605c 100644 --- a/drivers/gpu/drm/cirrus/cirrus_fbdev.c +++ b/drivers/gpu/drm/cirrus/cirrus_fbdev.c @@ -11,6 +11,7 @@ #include <linux/module.h> #include <drm/drmP.h> #include <drm/drm_fb_helper.h> +#include <drm/drm_crtc_helper.h>

#include <linux/fb.h>

@@ -291,6 +292,9 @@ int cirrus_fbdev_init(struct cirrus_device *cdev) return ret; } drm_fb_helper_single_add_all_connectors(&gfbdev->helper); + + /* disable all the possible outputs/crtcs before entering KMS mode */ + drm_helper_disable_unused_functions(cdev->dev); drm_fb_helper_initial_config(&gfbdev->helper, bpp_sel);

return 0; diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c index 1b6ba2d..ef3d33a 100644 --- a/drivers/gpu/drm/drm_fb_cma_helper.c +++ b/drivers/gpu/drm/drm_fb_cma_helper.c @@ -333,6 +333,9 @@ struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,

}

+ /* disable all the possible outputs/crtcs before entering KMS mode */ + drm_helper_disable_unused_functions(dev); + ret = drm_fb_helper_initial_config(helper, preferred_bpp); if (ret < 0) { dev_err(dev->dev, "Failed to set inital hw configuration.\n"); diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 3132d8a..f188344 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -1357,9 +1357,6 @@ bool drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel) struct drm_device *dev = fb_helper->dev; int count = 0;

- /* disable all the possible outputs/crtcs before entering KMS mode */ - drm_helper_disable_unused_functions(fb_helper->dev); - drm_fb_helper_parse_command_line(fb_helper);

count = drm_fb_helper_probe_connector_modes(fb_helper, diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c index 086d0f7..fe2a0f0 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c +++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c @@ -295,6 +295,9 @@ int exynos_drm_fbdev_init(struct drm_device *dev)

}

+ /* disable all the possible outputs/crtcs before entering KMS mode */ + drm_helper_disable_unused_functions(dev); + ret = drm_fb_helper_initial_config(helper, PREFERRED_BPP); if (ret < 0) { DRM_ERROR("failed to set up hw configuration.\n"); diff --git a/drivers/gpu/drm/gma500/framebuffer.c b/drivers/gpu/drm/gma500/framebuffer.c index c1ef37e..fee3bf8 100644 --- a/drivers/gpu/drm/gma500/framebuffer.c +++ b/drivers/gpu/drm/gma500/framebuffer.c @@ -616,6 +616,10 @@ int psb_fbdev_init(struct drm_device *dev) INTELFB_CONN_LIMIT);

drm_fb_helper_single_add_all_connectors(&fbdev->psb_fb_helper); + + /* disable all the possible outputs/crtcs before entering KMS mode */ + drm_helper_disable_unused_functions(dev); + drm_fb_helper_initial_config(&fbdev->psb_fb_helper, 32); return 0; } diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c index 33c4f1b..69b5b3c 100644 --- a/drivers/gpu/drm/i915/intel_fb.c +++ b/drivers/gpu/drm/i915/intel_fb.c @@ -258,6 +258,9 @@ void intel_fbdev_initial_config(struct drm_device *dev) { drm_i915_private_t *dev_priv = dev->dev_private;

+ /* disable all the possible outputs/crtcs before entering KMS mode */ + drm_helper_disable_unused_functions(dev); + /* Due to peculiar init order wrt to hpd handling this is separate. */ drm_fb_helper_initial_config(&dev_priv->fbdev->helper, 32); } diff --git a/drivers/gpu/drm/mgag200/mgag200_fb.c b/drivers/gpu/drm/mgag200/mgag200_fb.c index 5c69b43..5bded5b 100644 --- a/drivers/gpu/drm/mgag200/mgag200_fb.c +++ b/drivers/gpu/drm/mgag200/mgag200_fb.c @@ -13,6 +13,7 @@ #include <linux/module.h> #include <drm/drmP.h> #include <drm/drm_fb_helper.h> +#include <drm/drm_crtc_helper.h>

#include <linux/fb.h>

@@ -278,6 +279,10 @@ int mgag200_fbdev_init(struct mga_device *mdev) return ret; } drm_fb_helper_single_add_all_connectors(&mfbdev->helper); + + /* disable all the possible outputs/crtcs before entering KMS mode */ + drm_helper_disable_unused_functions(mdev->dev); + drm_fb_helper_initial_config(&mfbdev->helper, 32);

return 0; diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.c b/drivers/gpu/drm/nouveau/nouveau_fbcon.c index d4ecb4d..b1ebfe3 100644 --- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c +++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c @@ -491,6 +491,9 @@ nouveau_fbcon_init(struct drm_device *dev) else preferred_bpp = 32;

+ /* disable all the possible outputs/crtcs before entering KMS mode */ + drm_helper_disable_unused_functions(dev); + drm_fb_helper_initial_config(&fbcon->helper, preferred_bpp); return 0; } diff --git a/drivers/gpu/drm/radeon/radeon_fb.c b/drivers/gpu/drm/radeon/radeon_fb.c index 515e5ee..b48d1c8 100644 --- a/drivers/gpu/drm/radeon/radeon_fb.c +++ b/drivers/gpu/drm/radeon/radeon_fb.c @@ -379,6 +379,10 @@ int radeon_fbdev_init(struct radeon_device *rdev) }

drm_fb_helper_single_add_all_connectors(&rfbdev->helper); + + /* disable all the possible outputs/crtcs before entering KMS mode */ + drm_helper_disable_unused_functions(rdev->ddev); + drm_fb_helper_initial_config(&rfbdev->helper, bpp_sel); return 0; } diff --git a/drivers/gpu/drm/udl/udl_fb.c b/drivers/gpu/drm/udl/udl_fb.c index caa84f1..b610c3c 100644 --- a/drivers/gpu/drm/udl/udl_fb.c +++ b/drivers/gpu/drm/udl/udl_fb.c @@ -583,6 +583,10 @@ int udl_fbdev_init(struct drm_device *dev) }

drm_fb_helper_single_add_all_connectors(&ufbdev->helper); + + /* disable all the possible outputs/crtcs before entering KMS mode */ + drm_helper_disable_unused_functions(dev); + drm_fb_helper_initial_config(&ufbdev->helper, bpp_sel); return 0; } diff --git a/drivers/staging/omapdrm/omap_fbdev.c b/drivers/staging/omapdrm/omap_fbdev.c index 2728e37..7e66eb1 100644 --- a/drivers/staging/omapdrm/omap_fbdev.c +++ b/drivers/staging/omapdrm/omap_fbdev.c @@ -369,6 +369,10 @@ struct drm_fb_helper *omap_fbdev_init(struct drm_device *dev) }

drm_fb_helper_single_add_all_connectors(helper); + + /* disable all the possible outputs/crtcs before entering KMS mode */ + drm_helper_disable_unused_functions(dev); + drm_fb_helper_initial_config(helper, 32);

priv->fbdev = helper;

On Thu, Jan 24, 2013 at 10:20 AM, Daniel Vetter daniel.vetter@ffwll.ch wrote:

While doing the modeset rework for drm/i915 I've noticed that the fb helper is very liberal with the semantics of the ->set_config interface:

• It doesn't bother clearing stale modes (e.g. when unpluggint a

s/unpluggint/unplugging/

screen).

• It unconditionally sets and the fb, even if no mode will be set on a

s/and the fb/the fb/ ?

given crtc.

• The initial setup is a bit fun since we need to pick crtcs to decide the desired fb size, but also should set the modeset->fb pointer. Explain what's going on in the fixup code after the fb is allocated.

The crtc helper didn't really care, but the new i915 modeset infrastructure did, so I've had to add a bunch of special-cases to catch this.

Fix this all up and enforce the interface by converting the checks in drm/i915/intel_display.c to BUG_ONs.

maybe nitpicking, but how about a matching set of BUG_ONs in crtc helper, so someone messing with this code with a driver that still uses crtc helper would catch the same issues?

Anyways, basically seems reasonable.

But thanks for making me look at code that so far I've mostly tried to avoid looking at :-P

It does seem like the initial-config code could somehow be simpler than it is..

Anyways, while looking at that, it occurs to me that we should remove mode, and saved_fb from 'struct drm_fb_helper'

BR, -R

Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch

drivers/gpu/drm/drm_fb_helper.c | 27 +++++++++++++++++++++++---- drivers/gpu/drm/i915/intel_display.c | 11 +++-------- 2 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index dbf0020..5c73a12 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -689,7 +689,6 @@ int drm_fb_helper_set_par(struct fb_info *info) struct drm_fb_helper *fb_helper = info->par; struct drm_device *dev = fb_helper->dev; struct fb_var_screeninfo *var = &info->var;

•   struct drm_crtc *crtc;
    int ret;
    int i;
  
  

@@ -700,7 +699,6 @@ int drm_fb_helper_set_par(struct fb_info *info)

    drm_modeset_lock_all(dev);
    for (i = 0; i < fb_helper->crtc_count; i++) {

•           crtc = fb_helper->crtc_info[i].mode_set.crtc;
            ret = drm_mode_set_config_internal(&fb_helper->crtc_info[i].mode_set);
            if (ret) {
                    drm_modeset_unlock_all(dev);
  

@@ -841,9 +839,17 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,

    info = fb_helper->fbdev;

•   /* set the fb pointer */
  

•   /*
  

•    * Set the fb pointer - usually drm_setup_crtcs does this for hotplug
  

•    * events, but at init time drm_setup_crtcs needs to be called before
  

•    * the fb is allocated (since we need to figure out the desired size of
  

•    * the fb before we can allocate it ...). Hence we need to fix things up
  

•    * here again.
  

•    */
    for (i = 0; i < fb_helper->crtc_count; i++)
  

•           fb_helper->crtc_info[i].mode_set.fb = fb_helper->fb;
  

•           if (fb_helper->crtc_info[i].mode_set.num_connectors)
  

•                   fb_helper->crtc_info[i].mode_set.fb = fb_helper->fb;
  

•   if (new_fb) {
            info->var.pixclock = 0;
  

@@ -1314,6 +1320,7 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper) for (i = 0; i < fb_helper->crtc_count; i++) { modeset = &fb_helper->crtc_info[i].mode_set; modeset->num_connectors = 0;

•           modeset->fb = NULL;
    }
  
    for (i = 0; i < fb_helper->connector_count; i++) {
  

@@ -1330,9 +1337,21 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper) modeset->mode = drm_mode_duplicate(dev, fb_crtc->desired_mode); modeset->connectors[modeset->num_connectors++] = fb_helper->connector_info[i]->connector;

•                   modeset->fb = fb_helper->fb;
            }
    }
  
  

•   /* Clear out any old modes if there are no more connected outputs. */
  

•   for (i = 0; i < fb_helper->crtc_count; i++) {
  

•           modeset = &fb_helper->crtc_info[i].mode_set;
  

•           if (modeset->num_connectors == 0) {
  

•                   BUG_ON(modeset->fb);
  

•                   BUG_ON(modeset->num_connectors);
  

•                   if (modeset->mode)
  

•                           drm_mode_destroy(dev, modeset->mode);
  

•                   modeset->mode = NULL;
  

•           }
  

•   }
  

out: kfree(crtcs); kfree(modes); diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 055b24a..7e3dd0f 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -7940,14 +7940,9 @@ static int intel_crtc_set_config(struct drm_mode_set *set) BUG_ON(!set->crtc); BUG_ON(!set->crtc->helper_private);

•   if (!set->mode)
  

•           set->fb = NULL;
  

•   /* The fb helper likes to play gross jokes with ->mode_set_config.
  

•    * Unfortunately the crtc helper doesn't do much at all for this case,
  

•    * so we have to cope with this madness until the fb helper is fixed up. */
  

•   if (set->fb && set->num_connectors == 0)
  

•           return 0;
  

•   /* Enforce sane interface api - has been abused by the fb helper. */
  

•   BUG_ON(!set->mode && set->fb);
  

•   BUG_ON(set->fb && set->num_connectors == 0);
  
    if (set->fb) {
            DRM_DEBUG_KMS("[CRTC:%d] [FB:%d] #connectors=%d (x y) (%i %i)\n",
  

-- 1.7.10.4

---

dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel

Spotted by Rob Clark.

Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch --- include/drm/drm_fb_helper.h | 2 -- 1 file changed, 2 deletions(-)

diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h index a60311c..8ef4c63 100644 --- a/include/drm/drm_fb_helper.h +++ b/include/drm/drm_fb_helper.h @@ -77,9 +77,7 @@ struct drm_fb_helper_connector {

struct drm_fb_helper { struct drm_framebuffer *fb; - struct drm_framebuffer *saved_fb; struct drm_device *dev; - struct drm_display_mode *mode; int crtc_count; struct drm_fb_helper_crtc *crtc_info; int connector_count;

On Mon, Feb 11, 2013 at 7:25 PM, Daniel Vetter daniel.vetter@ffwll.ch wrote:

While doing the modeset rework for drm/i915 I've noticed that the fb helper is very liberal with the semantics of the ->set_config interface:

• It doesn't bother clearing stale modes (e.g. when unplugging a screen).
• It unconditionally sets the fb, even if no mode will be set on a given crtc.
• The initial setup is a bit fun since we need to pick crtcs to decide the desired fb size, but also should set the modeset->fb pointer. Explain what's going on in the fixup code after the fb is allocated.

The crtc helper didn't really care, but the new i915 modeset infrastructure did, so I've had to add a bunch of special-cases to catch this.

Fix this all up and enforce the interface by converting the checks in drm/i915/intel_display.c to BUG_ONs.

v2: Fix commit message spell fail spotted by Rob Clark.

Reviewed-by: Rob Clark robdclark@gmail.com

Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch

drivers/gpu/drm/drm_fb_helper.c | 27 +++++++++++++++++++++++---- drivers/gpu/drm/i915/intel_display.c | 11 +++-------- 2 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index d841b68..809ef99 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -689,7 +689,6 @@ int drm_fb_helper_set_par(struct fb_info *info) struct drm_fb_helper *fb_helper = info->par; struct drm_device *dev = fb_helper->dev; struct fb_var_screeninfo *var = &info->var;

•   struct drm_crtc *crtc;
    int ret;
    int i;
  
  

@@ -700,7 +699,6 @@ int drm_fb_helper_set_par(struct fb_info *info)

    drm_modeset_lock_all(dev);
    for (i = 0; i < fb_helper->crtc_count; i++) {

•           crtc = fb_helper->crtc_info[i].mode_set.crtc;
            ret = drm_mode_set_config_internal(&fb_helper->crtc_info[i].mode_set);
            if (ret) {
                    drm_modeset_unlock_all(dev);
  

@@ -841,9 +839,17 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,

    info = fb_helper->fbdev;

•   /* set the fb pointer */
  

•   /*
  

•    * Set the fb pointer - usually drm_setup_crtcs does this for hotplug
  

•    * events, but at init time drm_setup_crtcs needs to be called before
  

•    * the fb is allocated (since we need to figure out the desired size of
  

•    * the fb before we can allocate it ...). Hence we need to fix things up
  

•    * here again.
  

•    */
    for (i = 0; i < fb_helper->crtc_count; i++)
  

•           fb_helper->crtc_info[i].mode_set.fb = fb_helper->fb;
  

•           if (fb_helper->crtc_info[i].mode_set.num_connectors)
  

•                   fb_helper->crtc_info[i].mode_set.fb = fb_helper->fb;
  

•   if (new_fb) {
            info->var.pixclock = 0;
  

@@ -1314,6 +1320,7 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper) for (i = 0; i < fb_helper->crtc_count; i++) { modeset = &fb_helper->crtc_info[i].mode_set; modeset->num_connectors = 0;

•           modeset->fb = NULL;
    }
  
    for (i = 0; i < fb_helper->connector_count; i++) {
  

@@ -1330,9 +1337,21 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper) modeset->mode = drm_mode_duplicate(dev, fb_crtc->desired_mode); modeset->connectors[modeset->num_connectors++] = fb_helper->connector_info[i]->connector;

•                   modeset->fb = fb_helper->fb;
            }
    }
  
  

•   /* Clear out any old modes if there are no more connected outputs. */
  

•   for (i = 0; i < fb_helper->crtc_count; i++) {
  

•           modeset = &fb_helper->crtc_info[i].mode_set;
  

•           if (modeset->num_connectors == 0) {
  

•                   BUG_ON(modeset->fb);
  

•                   BUG_ON(modeset->num_connectors);
  

•                   if (modeset->mode)
  

•                           drm_mode_destroy(dev, modeset->mode);
  

•                   modeset->mode = NULL;
  

•           }
  

•   }
  

out: kfree(crtcs); kfree(modes); diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 24f2654..ca8d592 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -7978,14 +7978,9 @@ static int intel_crtc_set_config(struct drm_mode_set *set) BUG_ON(!set->crtc); BUG_ON(!set->crtc->helper_private);

•   if (!set->mode)
  

•           set->fb = NULL;
  

•   /* The fb helper likes to play gross jokes with ->mode_set_config.
  

•    * Unfortunately the crtc helper doesn't do much at all for this case,
  

•    * so we have to cope with this madness until the fb helper is fixed up. */
  

•   if (set->fb && set->num_connectors == 0)
  

•           return 0;
  

•   /* Enforce sane interface api - has been abused by the fb helper. */
  

•   BUG_ON(!set->mode && set->fb);
  

•   BUG_ON(set->fb && set->num_connectors == 0);
  
    if (set->fb) {
            DRM_DEBUG_KMS("[CRTC:%d] [FB:%d] #connectors=%d (x y) (%i %i)\n",
  

-- 1.7.10.4

On Thu, Jan 24, 2013 at 10:20 AM, Daniel Vetter daniel.vetter@ffwll.ch wrote:

The idea behind calling down into the driver's ->fb_probe function on each hotplug seems to be able to reallocate the backing storage (if e.g. a screen with higher resolution gets added). But that requires quite a bit of work in the fb helper itself, since currently we limit new screens to the currently allocated fb. An no kms driver supports fbdev fb resizing.

does an non kms fbdev driver support resizing? That might be a better argument ;-)

w/ framebuffer vaddr all over the place, teaching fbdev to resize seems like it might be kinda fun.. I guess if we really wanted to resize fbdev then we'd be better off beating all the console_lock vs notifier vs whatever else deadlocks so that we could reliably unregister and re-register a framebuffer on last-unplug / first-plug.

Reviewed-by: Rob Clark robdclark@gmail.com

So don't bother and start to simplify the code by calling drm_fb_helper_set_par directly from the fbdev hotplug function, since that's the only thing left in drm_fb_helper_single_fb_probe which does not concern itself with fb allocation and initial setup. Follow-on patches will streamline the initial setup code.

Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch

drivers/gpu/drm/drm_fb_helper.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 5c73a12..90c1117 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -859,8 +859,6 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper, dev_info(fb_helper->dev->dev, "fb%d: %s frame buffer device\n", info->node, info->fix.id);

•   } else {
  

•           drm_fb_helper_set_par(info);
    }
  
    /* Switch back to kernel console on panic */
  

@@ -1436,7 +1434,9 @@ int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper) drm_setup_crtcs(fb_helper); drm_modeset_unlock_all(dev);

•   return drm_fb_helper_single_fb_probe(fb_helper, bpp_sel);
  

•   drm_fb_helper_set_par(fb_helper->fbdev);
  

•   return 0;
  

} EXPORT_SYMBOL(drm_fb_helper_hotplug_event);

-- 1.7.10.4

---

dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel

On Thu, Jan 24, 2013 at 10:20 AM, Daniel Vetter daniel.vetter@ffwll.ch wrote:

No need to check whether we've allocated a new fb since we're not always doing that. Also, we always need to register the fbdev and add it to the panic notifier.

hmm, how is this not leading to a register_framebuffer() on every hotplug event?

BR, -R

Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch

drivers/gpu/drm/drm_fb_helper.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 90c1117..edbfcde 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -752,10 +752,14 @@ int drm_fb_helper_pan_display(struct fb_var_screeninfo *var, } EXPORT_SYMBOL(drm_fb_helper_pan_display);

+/*

• • Allocates the backing storage through the ->fb_probe callback and then
• • registers the fbdev and sets up the panic notifier.
• */

static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper, int preferred_bpp) {

•   int new_fb = 0;
  

•   int ret = 0;
    int crtc_count = 0;
    int i;
    struct fb_info *info;
  

@@ -833,9 +837,9 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper, }

    /* push down into drivers */

•   new_fb = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
  

•   if (new_fb < 0)
  

•           return new_fb;
  

•   ret = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
  

•   if (ret < 0)
  

•           return ret;
  
    info = fb_helper->fbdev;
  
  

@@ -851,15 +855,12 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper, fb_helper->crtc_info[i].mode_set.fb = fb_helper->fb;

•   if (new_fb) {
  

•           info->var.pixclock = 0;
  

•           if (register_framebuffer(info) < 0)
  

•                   return -EINVAL;
  

•           dev_info(fb_helper->dev->dev, "fb%d: %s frame buffer device\n",
  

•                           info->node, info->fix.id);
  

•   info->var.pixclock = 0;
  

•   if (register_framebuffer(info) < 0)
  

•           return -EINVAL;
  
  

•   }
  

•   dev_info(fb_helper->dev->dev, "fb%d: %s frame buffer device\n",
  

•                   info->node, info->fix.id);
  
    /* Switch back to kernel console on panic */
    /* multi card linked list maybe */
  

@@ -869,8 +870,8 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper, &paniced); register_sysrq_key('v', &sysrq_drm_fb_helper_restore_op); }

•   if (new_fb)
  

•           list_add(&fb_helper->kernel_fb_list, &kernel_fb_helper_list);
  

•   list_add(&fb_helper->kernel_fb_list, &kernel_fb_helper_list);
  
    return 0;
  

}

1.7.10.4

---

dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel

On Thu, Jan 24, 2013 at 11:20 AM, Daniel Vetter daniel.vetter@ffwll.ch wrote:

The fb helper lost its support for reallocating an fb completely, so no need to return special success values any more.

Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch

Reviewed-by: Rob Clark robdclark@gmail.com

---

drivers/gpu/drm/ast/ast_fb.c | 21 +++----------------- drivers/gpu/drm/cirrus/cirrus_fbdev.c | 22 +++------------------ drivers/gpu/drm/drm_fb_cma_helper.c | 17 +--------------- drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 30 +---------------------------- drivers/gpu/drm/gma500/framebuffer.c | 10 +--------- drivers/gpu/drm/i915/intel_fb.c | 21 +++----------------- drivers/gpu/drm/mgag200/mgag200_fb.c | 22 +++------------------ drivers/gpu/drm/nouveau/nouveau_fbcon.c | 22 +++------------------ drivers/gpu/drm/radeon/radeon_fb.c | 21 +++----------------- drivers/gpu/drm/udl/udl_fb.c | 22 +++------------------ drivers/staging/omapdrm/omap_fbdev.c | 17 +--------------- 11 files changed, 25 insertions(+), 200 deletions(-)

diff --git a/drivers/gpu/drm/ast/ast_fb.c b/drivers/gpu/drm/ast/ast_fb.c index 9bfd5ab..3a5a5e0 100644 --- a/drivers/gpu/drm/ast/ast_fb.c +++ b/drivers/gpu/drm/ast/ast_fb.c @@ -146,9 +146,10 @@ static int astfb_create_object(struct ast_fbdev *afbdev, return ret; }

-static int astfb_create(struct ast_fbdev *afbdev, +static int astfb_create(struct drm_fb_helper *helper, struct drm_fb_helper_surface_size *sizes) {

•   struct ast_fbdev *afbdev = (struct ast_fbdev *)helper;
    struct drm_device *dev = afbdev->helper.dev;
    struct drm_mode_fb_cmd2 mode_cmd;
    struct drm_framebuffer *fb;
  

@@ -249,26 +250,10 @@ static void ast_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green, *blue = ast_crtc->lut_b[regno] << 8; }

-static int ast_find_or_create_single(struct drm_fb_helper *helper,

•                                     struct drm_fb_helper_surface_size *sizes)
  

-{

•   struct ast_fbdev *afbdev = (struct ast_fbdev *)helper;
  

•   int new_fb = 0;
  

•   int ret;
  

•   if (!helper->fb) {
  

•           ret = astfb_create(afbdev, sizes);
  

•           if (ret)
  

•                   return ret;
  

•           new_fb = 1;
  

•   }
  

•   return new_fb;
  

-}

static struct drm_fb_helper_funcs ast_fb_helper_funcs = { .gamma_set = ast_fb_gamma_set, .gamma_get = ast_fb_gamma_get,

•   .fb_probe = ast_find_or_create_single,
  

•   .fb_probe = astfb_create,
  

};

static void ast_fbdev_destroy(struct drm_device *dev, diff --git a/drivers/gpu/drm/cirrus/cirrus_fbdev.c b/drivers/gpu/drm/cirrus/cirrus_fbdev.c index b869b8b..778a90b 100644 --- a/drivers/gpu/drm/cirrus/cirrus_fbdev.c +++ b/drivers/gpu/drm/cirrus/cirrus_fbdev.c @@ -121,9 +121,10 @@ static int cirrusfb_create_object(struct cirrus_fbdev *afbdev, return ret; }

-static int cirrusfb_create(struct cirrus_fbdev *gfbdev, +static int cirrusfb_create(struct drm_fb_helper *helper, struct drm_fb_helper_surface_size *sizes) {

•   struct cirrus_fbdev *gfbdev = (struct cirrus_fbdev *)helper;
    struct drm_device *dev = gfbdev->helper.dev;
    struct cirrus_device *cdev = gfbdev->helper.dev->dev_private;
    struct fb_info *info;
  

@@ -220,23 +221,6 @@ out_iounmap: return ret; }

-static int cirrus_fb_find_or_create_single(struct drm_fb_helper *helper,

•                                      struct drm_fb_helper_surface_size
  

•                                      *sizes)
  

-{

•   struct cirrus_fbdev *gfbdev = (struct cirrus_fbdev *)helper;
  

•   int new_fb = 0;
  

•   int ret;
  

•   if (!helper->fb) {
  

•           ret = cirrusfb_create(gfbdev, sizes);
  

•           if (ret)
  

•                   return ret;
  

•           new_fb = 1;
  

•   }
  

•   return new_fb;
  

-}

static int cirrus_fbdev_destroy(struct drm_device *dev, struct cirrus_fbdev *gfbdev) { @@ -268,7 +252,7 @@ static int cirrus_fbdev_destroy(struct drm_device *dev, static struct drm_fb_helper_funcs cirrus_fb_helper_funcs = { .gamma_set = cirrus_crtc_fb_gamma_set, .gamma_get = cirrus_crtc_fb_gamma_get,

•   .fb_probe = cirrus_fb_find_or_create_single,
  

•   .fb_probe = cirrusfb_create,
  

};

int cirrus_fbdev_init(struct cirrus_device *cdev) diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c index fcf9fa3..69814d2 100644 --- a/drivers/gpu/drm/drm_fb_cma_helper.c +++ b/drivers/gpu/drm/drm_fb_cma_helper.c @@ -275,23 +275,8 @@ err_drm_gem_cma_free_object: return ret; }

-static int drm_fbdev_cma_probe(struct drm_fb_helper *helper,

•   struct drm_fb_helper_surface_size *sizes)
  

-{

•   int ret = 0;
  

•   if (!helper->fb) {
  

•           ret = drm_fbdev_cma_create(helper, sizes);
  

•           if (ret < 0)
  

•                   return ret;
  

•           ret = 1;
  

•   }
  

•   return ret;
  

-}

static struct drm_fb_helper_funcs drm_fb_cma_helper_funcs = {

•   .fb_probe = drm_fbdev_cma_probe,
  

•   .fb_probe = drm_fbdev_cma_create,
  

};

/** diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c index 77d78cd..ca70b91 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c +++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c @@ -226,36 +226,8 @@ out: return ret; }

-static int exynos_drm_fbdev_probe(struct drm_fb_helper *helper,

•                              struct drm_fb_helper_surface_size *sizes)
  

-{

•   int ret = 0;
  

•   DRM_DEBUG_KMS("%s\n", __FILE__);
  

•   /*
  

•    * with !helper->fb, it means that this funcion is called first time
  

•    * and after that, the helper->fb would be used as clone mode.
  

•    */
  

•   if (!helper->fb) {
  

•           ret = exynos_drm_fbdev_create(helper, sizes);
  

•           if (ret < 0) {
  

•                   DRM_ERROR("failed to create fbdev.\n");
  

•                   return ret;
  

•           }
  

•           /*
  

•            * fb_helper expects a value more than 1 if succeed
  

•            * because register_framebuffer() should be called.
  

•            */
  

•           ret = 1;
  

•   }
  

•   return ret;
  

-}

static struct drm_fb_helper_funcs exynos_drm_fb_helper_funcs = {

•   .fb_probe =     exynos_drm_fbdev_probe,
  

•   .fb_probe =     exynos_drm_fbdev_create,
  

};

int exynos_drm_fbdev_init(struct drm_device *dev) diff --git a/drivers/gpu/drm/gma500/framebuffer.c b/drivers/gpu/drm/gma500/framebuffer.c index 7288b6d..f7a458c 100644 --- a/drivers/gpu/drm/gma500/framebuffer.c +++ b/drivers/gpu/drm/gma500/framebuffer.c @@ -545,9 +545,7 @@ static int psbfb_probe(struct drm_fb_helper *helper, struct psb_fbdev *psb_fbdev = (struct psb_fbdev *)helper; struct drm_device *dev = psb_fbdev->psb_fb_helper.dev; struct drm_psb_private *dev_priv = dev->dev_private;

•   int new_fb = 0;
    int bytespp;
  

•   int ret;
  
    bytespp = sizes->surface_bpp / 8;
    if (bytespp == 3)       /* no 24bit packed */
  

@@ -562,13 +560,7 @@ static int psbfb_probe(struct drm_fb_helper *helper, sizes->surface_depth = 16; }

•   if (!helper->fb) {
  

•           ret = psbfb_create(psb_fbdev, sizes);
  

•           if (ret)
  

•                   return ret;
  

•           new_fb = 1;
  

•   }
  

•   return new_fb;
  

•   return psbfb_create(psb_fbdev, sizes);
  

}

static struct drm_fb_helper_funcs psb_fb_helper_funcs = { diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c index 302bc63..3a0d16e 100644 --- a/drivers/gpu/drm/i915/intel_fb.c +++ b/drivers/gpu/drm/i915/intel_fb.c @@ -57,9 +57,10 @@ static struct fb_ops intelfb_ops = { .fb_debug_leave = drm_fb_helper_debug_leave, };

-static int intelfb_create(struct intel_fbdev *ifbdev, +static int intelfb_create(struct drm_fb_helper *helper, struct drm_fb_helper_surface_size *sizes) {

•   struct intel_fbdev *ifbdev = (struct intel_fbdev *)helper;
    struct drm_device *dev = ifbdev->helper.dev;
    struct drm_i915_private *dev_priv = dev->dev_private;
    struct fb_info *info;
  

@@ -181,26 +182,10 @@ out: return ret; }

-static int intel_fb_find_or_create_single(struct drm_fb_helper *helper,

•                                     struct drm_fb_helper_surface_size *sizes)
  

-{

•   struct intel_fbdev *ifbdev = (struct intel_fbdev *)helper;
  

•   int new_fb = 0;
  

•   int ret;
  

•   if (!helper->fb) {
  

•           ret = intelfb_create(ifbdev, sizes);
  

•           if (ret)
  

•                   return ret;
  

•           new_fb = 1;
  

•   }
  

•   return new_fb;
  

-}

static struct drm_fb_helper_funcs intel_fb_helper_funcs = { .gamma_set = intel_crtc_fb_gamma_set, .gamma_get = intel_crtc_fb_gamma_get,

•   .fb_probe = intel_fb_find_or_create_single,
  

•   .fb_probe = intelfb_create,
  

};

static void intel_fbdev_destroy(struct drm_device *dev, diff --git a/drivers/gpu/drm/mgag200/mgag200_fb.c b/drivers/gpu/drm/mgag200/mgag200_fb.c index 674f8fb..247bbcb 100644 --- a/drivers/gpu/drm/mgag200/mgag200_fb.c +++ b/drivers/gpu/drm/mgag200/mgag200_fb.c @@ -121,9 +121,10 @@ static int mgag200fb_create_object(struct mga_fbdev *afbdev, return ret; }

-static int mgag200fb_create(struct mga_fbdev *mfbdev, +static int mgag200fb_create(struct drm_fb_helper *helper, struct drm_fb_helper_surface_size *sizes) {

•   struct mga_fbdev *mfbdev = (struct mga_fbdev *)helper;
    struct drm_device *dev = mfbdev->helper.dev;
    struct drm_mode_fb_cmd2 mode_cmd;
    struct mga_device *mdev = dev->dev_private;
  

@@ -210,23 +211,6 @@ out: return ret; }

-static int mga_fb_find_or_create_single(struct drm_fb_helper *helper,

•                                      struct drm_fb_helper_surface_size
  

•                                      *sizes)
  

-{

•   struct mga_fbdev *mfbdev = (struct mga_fbdev *)helper;
  

•   int new_fb = 0;
  

•   int ret;
  

•   if (!helper->fb) {
  

•           ret = mgag200fb_create(mfbdev, sizes);
  

•           if (ret)
  

•                   return ret;
  

•           new_fb = 1;
  

•   }
  

•   return new_fb;
  

-}

static int mga_fbdev_destroy(struct drm_device *dev, struct mga_fbdev *mfbdev) { @@ -257,7 +241,7 @@ static int mga_fbdev_destroy(struct drm_device *dev, static struct drm_fb_helper_funcs mga_fb_helper_funcs = { .gamma_set = mga_crtc_fb_gamma_set, .gamma_get = mga_crtc_fb_gamma_get,

•   .fb_probe = mga_fb_find_or_create_single,
  

•   .fb_probe = mgag200fb_create,
  

};

int mgag200_fbdev_init(struct mga_device *mdev) diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.c b/drivers/gpu/drm/nouveau/nouveau_fbcon.c index 7b2d231..d983371 100644 --- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c +++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c @@ -251,9 +251,10 @@ nouveau_fbcon_zfill(struct drm_device *dev, struct nouveau_fbdev *fbcon) }

static int -nouveau_fbcon_create(struct nouveau_fbdev *fbcon, +nouveau_fbcon_create(struct drm_fb_helper *helper, struct drm_fb_helper_surface_size *sizes) {

•   struct nouveau_fbdev *fbcon = (struct nouveau_fbdev *)helper;
    struct drm_device *dev = fbcon->dev;
    struct nouveau_drm *drm = nouveau_drm(dev);
    struct nouveau_device *device = nv_device(drm->device);
  

@@ -388,23 +389,6 @@ out: return ret; }

-static int -nouveau_fbcon_find_or_create_single(struct drm_fb_helper *helper,

•                               struct drm_fb_helper_surface_size *sizes)
  

-{

•   struct nouveau_fbdev *fbcon = (struct nouveau_fbdev *)helper;
  

•   int new_fb = 0;
  

•   int ret;
  

•   if (!helper->fb) {
  

•           ret = nouveau_fbcon_create(fbcon, sizes);
  

•           if (ret)
  

•                   return ret;
  

•           new_fb = 1;
  

•   }
  

•   return new_fb;
  

-}

void nouveau_fbcon_output_poll_changed(struct drm_device *dev) { @@ -450,7 +434,7 @@ void nouveau_fbcon_gpu_lockup(struct fb_info *info) static struct drm_fb_helper_funcs nouveau_fbcon_helper_funcs = { .gamma_set = nouveau_fbcon_gamma_set, .gamma_get = nouveau_fbcon_gamma_get,

•   .fb_probe = nouveau_fbcon_find_or_create_single,
  

•   .fb_probe = nouveau_fbcon_create,
  

};

diff --git a/drivers/gpu/drm/radeon/radeon_fb.c b/drivers/gpu/drm/radeon/radeon_fb.c index a44b386..b6c73b6 100644 --- a/drivers/gpu/drm/radeon/radeon_fb.c +++ b/drivers/gpu/drm/radeon/radeon_fb.c @@ -187,9 +187,10 @@ out_unref: return ret; }

-static int radeonfb_create(struct radeon_fbdev *rfbdev, +static int radeonfb_create(struct drm_fb_helper *helper, struct drm_fb_helper_surface_size *sizes) {

•   struct radeon_fbdev *rfbdev = (struct radeon_fbdev *)helper;
    struct radeon_device *rdev = rfbdev->rdev;
    struct fb_info *info;
    struct drm_framebuffer *fb = NULL;
  

@@ -300,22 +301,6 @@ out_unref: return ret; }

-static int radeon_fb_find_or_create_single(struct drm_fb_helper *helper,

•                                      struct drm_fb_helper_surface_size *sizes)
  

-{

•   struct radeon_fbdev *rfbdev = (struct radeon_fbdev *)helper;
  

•   int new_fb = 0;
  

•   int ret;
  

•   if (!helper->fb) {
  

•           ret = radeonfb_create(rfbdev, sizes);
  

•           if (ret)
  

•                   return ret;
  

•           new_fb = 1;
  

•   }
  

•   return new_fb;
  

-}

void radeon_fb_output_poll_changed(struct radeon_device *rdev) { drm_fb_helper_hotplug_event(&rdev->mode_info.rfbdev->helper); @@ -349,7 +334,7 @@ static int radeon_fbdev_destroy(struct drm_device *dev, struct radeon_fbdev *rfb static struct drm_fb_helper_funcs radeon_fb_helper_funcs = { .gamma_set = radeon_crtc_fb_gamma_set, .gamma_get = radeon_crtc_fb_gamma_get,

•   .fb_probe = radeon_fb_find_or_create_single,
  

•   .fb_probe = radeonfb_create,
  

};

int radeon_fbdev_init(struct radeon_device *rdev) diff --git a/drivers/gpu/drm/udl/udl_fb.c b/drivers/gpu/drm/udl/udl_fb.c index 7d40cb7..1b51579 100644 --- a/drivers/gpu/drm/udl/udl_fb.c +++ b/drivers/gpu/drm/udl/udl_fb.c @@ -440,9 +440,10 @@ udl_framebuffer_init(struct drm_device *dev, }

-static int udlfb_create(struct udl_fbdev *ufbdev, +static int udlfb_create(struct drm_fb_helper *helper, struct drm_fb_helper_surface_size *sizes) {

•   struct udl_fbdev *ufbdev = (struct udl_fbdev *)helper;
    struct drm_device *dev = ufbdev->helper.dev;
    struct fb_info *info;
    struct device *device = &dev->usbdev->dev;
  

@@ -520,27 +521,10 @@ out: return ret; }

-static int udl_fb_find_or_create_single(struct drm_fb_helper *helper,

•                                   struct drm_fb_helper_surface_size *sizes)
  

-{

•   struct udl_fbdev *ufbdev = (struct udl_fbdev *)helper;
  

•   int new_fb = 0;
  

•   int ret;
  

•   if (!helper->fb) {
  

•           ret = udlfb_create(ufbdev, sizes);
  

•           if (ret)
  

•                   return ret;
  

•           new_fb = 1;
  

•   }
  

•   return new_fb;
  

-}

static struct drm_fb_helper_funcs udl_fb_helper_funcs = { .gamma_set = udl_crtc_fb_gamma_set, .gamma_get = udl_crtc_fb_gamma_get,

•   .fb_probe = udl_fb_find_or_create_single,
  

•   .fb_probe = udlfb_create,
  

};

static void udl_fbdev_destroy(struct drm_device *dev, diff --git a/drivers/staging/omapdrm/omap_fbdev.c b/drivers/staging/omapdrm/omap_fbdev.c index 6ccaf54..11f7dcb 100644 --- a/drivers/staging/omapdrm/omap_fbdev.c +++ b/drivers/staging/omapdrm/omap_fbdev.c @@ -296,25 +296,10 @@ static void omap_crtc_fb_gamma_get(struct drm_crtc *crtc, DBG("fbdev: get gamma"); }

-static int omap_fbdev_probe(struct drm_fb_helper *helper,

•           struct drm_fb_helper_surface_size *sizes)
  

-{

•   int new_fb = 0;
  

•   int ret;
  

•   if (!helper->fb) {
  

•           ret = omap_fbdev_create(helper, sizes);
  

•           if (ret)
  

•                   return ret;
  

•           new_fb = 1;
  

•   }
  

•   return new_fb;
  

-}

static struct drm_fb_helper_funcs omap_fb_helper_funcs = { .gamma_set = omap_crtc_fb_gamma_set, .gamma_get = omap_crtc_fb_gamma_get,

•   .fb_probe = omap_fbdev_probe,
  

•   .fb_probe = omap_fbdev_create,
  

};

static struct drm_fb_helper *get_fb(struct fb_info *fbi)

1.7.10.4

---

dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel

Now that the fbdev helper interface for drivers is trimmed down, update the kerneldoc for all the remaining exported functions.

I've tried to beat the DocBook a bit by reordering the function references a bit into a more sensible ordering. But that didn't work out at all. Hence just extend the in-code DOC: section a bit.

Also remove the LOCKING: sections - especially for the setup functions they're totally bogus. But that's not a documentation problem, but simply an artifact of the current rather hazardous locking around drm init and even more so around fbdev setup ...

v2: Some further improvements: - Also add documentation for drm_fb_helper_single_add_all_connectors, Dave Airlie didn't want me to kill this one from the fb helper interface. - Update docs for drm_fb_helper_fill_var/fix - they should be used from the driver's ->fb_probe callback to setup the fbdev info structure. - Clarify what the ->fb_probe callback should all do - it needs to setup both the fbdev info and allocate the drm framebuffer used as backing storage. - Add basic documentaation for the drm_fb_helper_funcs driver callback vfunc.

Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch

moar kerneldoc --- Documentation/DocBook/drm.tmpl | 1 + drivers/gpu/drm/drm_fb_helper.c | 146 +++++++++++++++++++++++++++++++++++---- include/drm/drm_fb_helper.h | 11 +++ 3 files changed, 143 insertions(+), 15 deletions(-)

diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl index 6c11d77..14ad829 100644 --- a/Documentation/DocBook/drm.tmpl +++ b/Documentation/DocBook/drm.tmpl @@ -2139,6 +2139,7 @@ void intel_crt_init(struct drm_device *dev) <title>fbdev Helper Functions Reference</title> !Pdrivers/gpu/drm/drm_fb_helper.c fbdev helpers !Edrivers/gpu/drm/drm_fb_helper.c +!Iinclude/drm/drm_fb_helper.h </sect2> <sect2> <title>Display Port Helper Functions Reference</title> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 5a92470..a7538cc 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -52,9 +52,34 @@ static LIST_HEAD(kernel_fb_helper_list); * mode setting driver. They can be used mostly independantely from the crtc * helper functions used by many drivers to implement the kernel mode setting * interfaces. + * + * Initialization is done as a three-step process with drm_fb_helper_init(), + * drm_fb_helper_single_add_all_connectors() and drm_fb_helper_initial_config(). + * Drivers with fancier requirements than the default beheviour can override the + * second step with their own code. Teardown is done with drm_fb_helper_fini(). + * + * At runtime drivers should restore the fbdev console by calling + * drm_fb_helper_restore_fbdev_mode() from their ->lastclose callback. They can + * also notify the fb helper code from updates to the output configuration by + * calling drm_fb_helper_hotplug_event(). + * + * All other functions exported by the fb helper library can be used to + * implement the fbdev driver interface by the driver. */

-/* simple single crtc case helper function */ +/** + * drm_fb_helper_single_add_all_connectors() - add all connectors to fbdev + * emulation helper + * @fb_helper: fbdev initialized with drm_fb_helper_init + * + * This functions adds all the available connectors for use with the given + * fb_helper. This is a separate step to allow drivers to freely assign + * connectors to the fbdev, e.g. if some are reserved for special purposes or + * not adequate to be used for the fbcon. + * + * Since this is part of the initial setup before the fbdev is published, no + * locking is required. + */ int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper) { struct drm_device *dev = fb_helper->dev; @@ -163,6 +188,10 @@ static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc) crtc->funcs->gamma_set(crtc, r_base, g_base, b_base, 0, crtc->gamma_size); }

+/** + * drm_fb_helper_debug_enter - implementation for ->fb_debug_enter + * @info: fbdev registered by the helper. + */ int drm_fb_helper_debug_enter(struct fb_info *info) { struct drm_fb_helper *helper = info->par; @@ -208,6 +237,10 @@ static struct drm_framebuffer *drm_mode_config_fb(struct drm_crtc *crtc) return NULL; }

+/** + * drm_fb_helper_debug_leave - implementation for ->fb_debug_leave + * @info: fbdev registered by the helper. + */ int drm_fb_helper_debug_leave(struct fb_info *info) { struct drm_fb_helper *helper = info->par; @@ -243,9 +276,9 @@ EXPORT_SYMBOL(drm_fb_helper_debug_leave); * drm_fb_helper_restore_fbdev_mode - restore fbdev configuration * @fb_helper: fbcon to restore * - * This should be called from driver's drm->lastclose callback when implementing - * an fbcon on top of kms using this helper. This ensures that the user isn't - * greeted with a black screen when e.g. X dies. + * This should be called from driver's drm <code>->lastclose</code> callback + * when implementing an fbcon on top of kms using this helper. This ensures that + * the user isn't greeted with a black screen when e.g. X dies. */ bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper) { @@ -378,6 +411,11 @@ static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode) drm_modeset_unlock_all(dev); }

+/** + * drm_fb_helper_blank - implementation for ->fb_blank + * @blank: desired blanking state + * @info: fbdev registered by the helper. + */ int drm_fb_helper_blank(int blank, struct fb_info *info) { switch (blank) { @@ -421,6 +459,24 @@ static void drm_fb_helper_crtc_free(struct drm_fb_helper *helper) kfree(helper->crtc_info); }

+/** + * drm_fb_helper_init - initialize a drm_fb_helper structure + * @dev: drm device + * @fb_helper: driver-allocated fbdev helper structure to initialize + * @crtc_count: crtc count + * @max_conn_count: max connector count + * + * This allocates the structures for the fbdev helper with the given limits. + * Note that this won't yet touch the hw (through the driver interfaces) nor + * register the fbdev. This is only done in drm_fb_helper_initial_config() to + * allow driver writes more control over the exact init sequence. + * + * Drivers must also set fb_helper->funcs before calling + * drm_fb_helper_initial_config(). + * + * RETURNS: + * Zero if everything went ok, nonzero otherwise. + */ int drm_fb_helper_init(struct drm_device *dev, struct drm_fb_helper *fb_helper, int crtc_count, int max_conn_count) @@ -549,6 +605,11 @@ static int setcolreg(struct drm_crtc *crtc, u16 red, u16 green, return 0; }

+/** + * drm_fb_helper_setcmap - implementation for ->fb_setcmap + * @cmap: cmap to set + * @info: fbdev registered by the helper. + */ int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info) { struct drm_fb_helper *fb_helper = info->par; @@ -588,6 +649,11 @@ int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info) } EXPORT_SYMBOL(drm_fb_helper_setcmap);

+/** + * drm_fb_helper_check_var - implementation for ->fb_check_var + * @var: screeninfo to check + * @info: fbdev registered by the helper. + */ int drm_fb_helper_check_var(struct fb_var_screeninfo *var, struct fb_info *info) { @@ -680,7 +746,14 @@ int drm_fb_helper_check_var(struct fb_var_screeninfo *var, } EXPORT_SYMBOL(drm_fb_helper_check_var);

-/* this will let fbcon do the mode init */ +/** + * drm_fb_helper_set_par - implementation for ->fb_set_par + * @info: fbdev registered by the helper. + * + * This will let fbcon do the mode init and is called at initialization time by + * the fbdev core when registering the driver, and later on through the hotplug + * callback. + */ int drm_fb_helper_set_par(struct fb_info *info) { struct drm_fb_helper *fb_helper = info->par; @@ -712,6 +785,11 @@ int drm_fb_helper_set_par(struct fb_info *info) } EXPORT_SYMBOL(drm_fb_helper_set_par);

+/** + * drm_fb_helper_pan_display - implementation for ->fb_pan_display + * @var: updated screen information + * @info: fbdev registered by the helper. + */ int drm_fb_helper_pan_display(struct fb_var_screeninfo *var, struct fb_info *info) { @@ -750,8 +828,9 @@ int drm_fb_helper_pan_display(struct fb_var_screeninfo *var, EXPORT_SYMBOL(drm_fb_helper_pan_display);

/* - * Allocates the backing storage through the ->fb_probe callback and then - * registers the fbdev and sets up the panic notifier. + * Allocates the backing storage and sets up the fbdev info structure through + * the ->fb_probe callback and then registers the fbdev and sets up the panic + * notifier. */ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper, int preferred_bpp) @@ -873,6 +952,19 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper, return 0; }

+/** + * drm_fb_helper_fill_fix - initializes fixed fbdev information + * @info: fbdev registered by the helper. + * @pitch: desired pitch + * @depth: desired depth + * + * Helper to fill in the fixed fbdev information useful for a non-accelerated + * fbdev emulations. Drivers which support acceleration methods which impose + * additional constraints need to set up their own limits. + * + * Drivers should call this (or their equivalent setup code) from their + * <code>->fb_probe</code> callback. + */ void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch, uint32_t depth) { @@ -893,6 +985,20 @@ void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch, } EXPORT_SYMBOL(drm_fb_helper_fill_fix);

+/** + * drm_fb_helper_fill_var - initalizes variable fbdev information + * @info: fbdev instance to set up + * @fb_helper: fb helper instance to use as template + * @fb_width: desired fb width + * @fb_height: desired fb height + * + * Sets up the variable fbdev metainformation from the given fb helper instance + * and the drm framebuffer allocated in <code>fb_helper->fb</code>. + * + * Drivers should call this (or their equivalent setup code) from their + * <code>->fb_probe</code> callback after having allocated the fbdev backing + * storage framebuffer. + */ void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helper, uint32_t fb_width, uint32_t fb_height) { @@ -1355,18 +1461,23 @@ out: }

/** - * drm_helper_initial_config - setup a sane initial connector configuration + * drm_fb_helper_initial_config - setup a sane initial connector configuration * @fb_helper: fb_helper device struct * @bpp_sel: bpp value to use for the framebuffer configuration * - * LOCKING: - * Called at init time by the driver to set up the @fb_helper initial - * configuration, must take the mode config lock. - * * Scans the CRTCs and connectors and tries to put together an initial setup. * At the moment, this is a cloned configuration across all heads with * a new framebuffer object as the backing store. * + * Note that this also registers the fbdev and so allows userspace to call into + * the driver through the fbdev interfaces. + * + * This function will call down into the <code>->fb_probe</code> callback to let + * the driver allocate and initialize the fbdev info structure and the drm + * framebuffer used to back the fbdev. drm_fb_helper_fill_var() and + * drm_fb_helper_fill_fix() are provided as helpers to setup simple default + * values for the fbdev info structure. + * * RETURNS: * Zero if everything went ok, nonzero otherwise. */ @@ -1397,12 +1508,17 @@ EXPORT_SYMBOL(drm_fb_helper_initial_config); * probing all the outputs attached to the fb * @fb_helper: the drm_fb_helper * - * LOCKING: - * Called at runtime, must take mode config lock. - * * Scan the connectors attached to the fb_helper and try to put together a * setup after *notification of a change in output configuration. * + * Called at runtime, takes the mode config locks to be able to check/change the + * modeset configuration. Must be run from process context (which usually means + * either the output polling work or a work item launch from the driver's + * hotplug interrupt). + * + * Note that the driver must ensure that this is only called _after_ the fb has + * been fully set up, i.e. after the call to drm_fb_helper_initial_config. + * * RETURNS: * 0 on success and a non-zero error code otherwise. */ diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h index 973402d..3c30297 100644 --- a/include/drm/drm_fb_helper.h +++ b/include/drm/drm_fb_helper.h @@ -48,6 +48,17 @@ struct drm_fb_helper_surface_size { u32 surface_depth; };

+/** + * struct drm_fb_helper_funcs - driver callbacks for the fbdev emulation library + * @gamma_set: - Set the given lut register on the given crtc. + * @gamma_get: - Read the given lut register on the given crtc, used to safe the + * current lut when force-restoring the fbdev for e.g. kdbg. + * @fb_probe: - Driver callback to allocate and initialize the fbdev info + * structure. Futhermore it also needs to allocate the drm + * framebuffer used to back the fbdev. + * + * Driver callbacks used by the fbdev emulation helper library. + */ struct drm_fb_helper_funcs { void (*gamma_set)(struct drm_crtc *crtc, u16 red, u16 green, u16 blue, int regno);

On Fri, Feb 01, 2013 at 01:21:29PM +0100, Laurent Pinchart wrote:

Hi Daniel,

Thanks for improving the documentation :-)

On Sunday 27 January 2013 18:42:16 Daniel Vetter wrote:

...

Now that the fbdev helper interface for drivers is trimmed down, update the kerneldoc for all the remaining exported functions.

I've tried to beat the DocBook a bit by reordering the function references a bit into a more sensible ordering. But that didn't work out at all. Hence just extend the in-code DOC: section a bit.

Also remove the LOCKING: sections - especially for the setup functions they're totally bogus. But that's not a documentation problem, but simply an artifact of the current rather hazardous locking around drm init and even more so around fbdev setup ...

Please see below for comments (I've reflowed the text to ease review).

...

v2: Some further improvements:

• Also add documentation for drm_fb_helper_single_add_all_connectors, Dave Airlie didn't want me to kill this one from the fb helper interface.
• Update docs for drm_fb_helper_fill_var/fix - they should be used from the driver's ->fb_probe callback to setup the fbdev info structure.
• Clarify what the ->fb_probe callback should all do - it needs to setup both the fbdev info and allocate the drm framebuffer used as backing storage.
• Add basic documentaation for the drm_fb_helper_funcs driver callback vfunc.

Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch

moar kerneldoc

Documentation/DocBook/drm.tmpl | 1 + drivers/gpu/drm/drm_fb_helper.c | 146 ++++++++++++++++++++++++++++++++---- include/drm/drm_fb_helper.h | 11 +++ 3 files changed, 143 insertions(+), 15 deletions(-)

diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl index 6c11d77..14ad829 100644 --- a/Documentation/DocBook/drm.tmpl +++ b/Documentation/DocBook/drm.tmpl @@ -2139,6 +2139,7 @@ void intel_crt_init(struct drm_device *dev) <title>fbdev Helper Functions Reference</title> !Pdrivers/gpu/drm/drm_fb_helper.c fbdev helpers !Edrivers/gpu/drm/drm_fb_helper.c +!Iinclude/drm/drm_fb_helper.h </sect2> <sect2> <title>Display Port Helper Functions Reference</title> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 5a92470..a7538cc 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -52,9 +52,34 @@ static LIST_HEAD(kernel_fb_helper_list);

• mode setting driver. They can be used mostly independantely from the

Now that you have removed one of the dependencies on the crtc helpers in your "drm/fb-helper: don't disable everything in initial_config" patch, are there others ? If not you can s/mostly //.

It's getting better, but a few of the driver callbacks used by the fb helper are still in the crtc helper function tables. And there's the fb helper private way to safe/restore gamma tables. But at least semantically there's no dependency any longer after these patches I think.

...

• crtc helper functions used by many drivers to implement the kernel mode
• setting interfaces.

• • Initialization is done as a three-step process with
• • drm_fb_helper_init(), drm_fb_helper_single_add_all_connectors() and
• • drm_fb_helper_initial_config(). Drivers with fancier requirements than
• • the default beheviour can override the second step with their own code.
• • Teardown is done with drm_fb_helper_fini().
• • At runtime drivers should restore the fbdev console by calling
• • drm_fb_helper_restore_fbdev_mode() from their ->lastclose callback. They
• • can also notify the fb helper code from updates to the output

Is it "can" or "must" ? If "can", in what conditions should they call drm_fb_helper_restore_fbdev_mode() and in what conditions shouldn't they ?

I've figured that hpd support is optional, hence no "must". I've opted for a should instead. Also added a bit of text to suggest a good place to put this call.

...

• • configuration by calling drm_fb_helper_hotplug_event().
• • All other functions exported by the fb helper library can be used to
• • implement the fbdev driver interface by the driver.
  */

-/* simple single crtc case helper function */ +/**

• • drm_fb_helper_single_add_all_connectors() - add all connectors to fbdev

• • 			       emulation helper
    

• • @fb_helper: fbdev initialized with drm_fb_helper_init
• • This functions adds all the available connectors for use with the given
• • fb_helper. This is a separate step to allow drivers to freely assign or
• • connectors to the fbdev, e.g. if some are reserved for special purposes
• • not adequate to be used for the fbcon.
• • Since this is part of the initial setup before the fbdev is published,
• • no locking is required.
• */

int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper) { struct drm_device *dev = fb_helper->dev; @@ -163,6 +188,10 @@ static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc) crtc->funcs->gamma_set(crtc, r_base, g_base, b_base, 0, crtc->gamma_size); }

+/**

• • drm_fb_helper_debug_enter - implementation for ->fb_debug_enter
• • @info: fbdev registered by the helper.
• */

int drm_fb_helper_debug_enter(struct fb_info *info) { struct drm_fb_helper *helper = info->par; @@ -208,6 +237,10 @@ static struct drm_framebuffer *drm_mode_config_fb(struct drm_crtc *crtc) return NULL; }

+/**

• • drm_fb_helper_debug_leave - implementation for ->fb_debug_leave
• • @info: fbdev registered by the helper.
• */

int drm_fb_helper_debug_leave(struct fb_info *info) { struct drm_fb_helper *helper = info->par; @@ -243,9 +276,9 @@ EXPORT_SYMBOL(drm_fb_helper_debug_leave);

• drm_fb_helper_restore_fbdev_mode - restore fbdev configuration
• @fb_helper: fbcon to restore

• • This should be called from driver's drm->lastclose callback when
• • implementing an fbcon on top of kms using this helper. This ensures that
• • the user isn't greeted with a black screen when e.g. X dies.

• • This should be called from driver's drm <code>->lastclose</code>

The resulting HTML is

&lt;code&gt;-&gt;lastclose&lt;/code&gt;

I'm not sure that's what you want :-)

Nope, killed them all.

...

• • callback when implementing an fbcon on top of kms using this helper.
• • This ensures that the user isn't greeted with a black screen when e.g.
• • X dies.
  */

bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper) { @@ -378,6 +411,11 @@ static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode) drm_modeset_unlock_all(dev); }

+/**

• • drm_fb_helper_blank - implementation for ->fb_blank
• • @blank: desired blanking state
• • @info: fbdev registered by the helper.

Nitpicking here, shouldn't you either use a full stop at the end of each argument, or no full stop at all (this applies to the other functions as well) ?

Copy&pasta, full stop dropped everywhere.

...

• */

int drm_fb_helper_blank(int blank, struct fb_info *info) { switch (blank) { @@ -421,6 +459,24 @@ static void drm_fb_helper_crtc_free(struct drm_fb_helper *helper) kfree(helper->crtc_info); }

+/**

• • drm_fb_helper_init - initialize a drm_fb_helper structure
• • @dev: drm device
• • @fb_helper: driver-allocated fbdev helper structure to initialize
• • @crtc_count: crtc count
• • @max_conn_count: max connector count
• • This allocates the structures for the fbdev helper with the given
• • limits. Note that this won't yet touch the hw (through the driver

s/hw/hardware/ ?

It might be a good idea to add a small description of the crtc_count parameter.

Done. All the other corrections below I've also applied.

Thanks, Daniel

Otherwise the system will burn even brighter and worse, leave the user wondering what's going on exactly.

Since we already have a panic handler which will (try) to restore the entire fbdev console mode, we can just bail out. Inspired by a patch from Konstantin Khlebnikov. The callchain leading to this, cut&pasted from Konstantin's original patch:

callstack: panic() bust_spinlocks(1) unblank_screen() vc->vc_sw->con_blank() fbcon_blank() fb_blank() info->fbops->fb_blank() drm_fb_helper_blank() drm_fb_helper_dpms() drm_modeset_lock_all() mutex_lock(&dev->mode_config.mutex)

Note that the entire locking in the fb helper around panic/sysrq and kdbg is ... non-existant. So we have a decent change of blowing up everything. But since reworking this ties in with funny concepts like the fbdev notifier chain or the impressive things which happen around console_lock while oopsing, I'll leave that as an exercise for braver souls than me.

v2: Drop the -EBUSY return value I've copied, we don't need it since the we'll take care of things ourselves anyway.

Cc: Konstantin Khlebnikov khlebnikov@openvz.org Cc: Andrew Morton akpm@linux-foundation.org References: https://patchwork.kernel.org/patch/1878181/ Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_fb_helper.c | 8 ++++++++ 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index a7538cc..01099b5 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -386,6 +386,14 @@ static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode) int i, j;

/* + * fbdev->blank can be called from irq context in case of a panic. + * Since we already have our own special panic handler which will + * restore the fbdev console mode completely, just bail out early. + */ + if (oops_in_progress) + return; + + /* * For each CRTC in this fb, turn the connectors on/off. */ drm_modeset_lock_all(dev);