From: Laurent Pinchart laurent.pinchart@ideasonboard.com
Implement a custom .atomic_commit() handler that supports asynchronous commits using a work queue. This can be used for userspace-driven asynchronous commits, as well as for an atomic page flip implementation.
Signed-off-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Signed-off-by: Tomi Valkeinen tomi.valkeinen@ti.com --- drivers/gpu/drm/omapdrm/omap_drv.c | 113 ++++++++++++++++++++++++++++++++++++- drivers/gpu/drm/omapdrm/omap_drv.h | 8 +++ 2 files changed, 120 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c b/drivers/gpu/drm/omapdrm/omap_drv.c index ec0ae4220e72..72a5a88a6419 100644 --- a/drivers/gpu/drm/omapdrm/omap_drv.c +++ b/drivers/gpu/drm/omapdrm/omap_drv.c @@ -17,6 +17,9 @@ * this program. If not, see http://www.gnu.org/licenses/. */
+#include <linux/wait.h> + +#include <drm/drm_atomic.h> #include <drm/drm_atomic_helper.h> #include <drm/drm_crtc_helper.h> #include <drm/drm_fb_helper.h> @@ -56,11 +59,117 @@ static void omap_fb_output_poll_changed(struct drm_device *dev) drm_fb_helper_hotplug_event(priv->fbdev); }
+struct omap_atomic_state_commit { + struct work_struct work; + struct drm_device *dev; + struct drm_atomic_state *state; + u32 crtcs; +}; + +static void omap_atomic_complete(struct omap_atomic_state_commit *commit) +{ + struct drm_device *dev = commit->dev; + struct omap_drm_private *priv = dev->dev_private; + struct drm_atomic_state *old_state = commit->state; + + /* Apply the atomic update. */ + drm_atomic_helper_commit_modeset_disables(dev, old_state); + drm_atomic_helper_commit_planes(dev, old_state); + drm_atomic_helper_commit_modeset_enables(dev, old_state); + + drm_atomic_helper_wait_for_vblanks(dev, old_state); + + drm_atomic_helper_cleanup_planes(dev, old_state); + + drm_atomic_state_free(old_state); + + /* Complete the commit, wake up any waiter. */ + spin_lock(&priv->commit.lock); + priv->commit.pending &= ~commit->crtcs; + spin_unlock(&priv->commit.lock); + + wake_up_all(&priv->commit.wait); + + kfree(commit); +} + +static void omap_atomic_work(struct work_struct *work) +{ + struct omap_atomic_state_commit *commit = + container_of(work, struct omap_atomic_state_commit, work); + + omap_atomic_complete(commit); +} + +static bool omap_atomic_is_pending(struct omap_drm_private *priv, + struct omap_atomic_state_commit *commit) +{ + bool pending; + + spin_lock(&priv->commit.lock); + pending = priv->commit.pending & commit->crtcs; + spin_unlock(&priv->commit.lock); + + return pending; +} + +static int omap_atomic_commit(struct drm_device *dev, + struct drm_atomic_state *state, bool async) +{ + struct omap_drm_private *priv = dev->dev_private; + struct omap_atomic_state_commit *commit; + unsigned int i; + int ret; + + ret = drm_atomic_helper_prepare_planes(dev, state); + if (ret) + return ret; + + /* Allocate the commit object. */ + commit = kzalloc(sizeof(*commit), GFP_KERNEL); + if (commit == NULL) { + ret = -ENOMEM; + goto error; + } + + INIT_WORK(&commit->work, omap_atomic_work); + commit->dev = dev; + commit->state = state; + + /* Wait until all affected CRTCs have completed previous commits and + * mark them as pending. + */ + for (i = 0; i < dev->mode_config.num_crtc; ++i) { + if (state->crtcs[i]) + commit->crtcs |= 1 << drm_crtc_index(state->crtcs[i]); + } + + wait_event(priv->commit.wait, !omap_atomic_is_pending(priv, commit)); + + spin_lock(&priv->commit.lock); + priv->commit.pending |= commit->crtcs; + spin_unlock(&priv->commit.lock); + + /* Swap the state, this is the point of no return. */ + drm_atomic_helper_swap_state(dev, state); + + if (async) + schedule_work(&commit->work); + else + omap_atomic_complete(commit); + + return 0; + +error: + drm_atomic_helper_cleanup_planes(dev, state); + return ret; +} + static const struct drm_mode_config_funcs omap_mode_config_funcs = { .fb_create = omap_framebuffer_create, .output_poll_changed = omap_fb_output_poll_changed, .atomic_check = drm_atomic_helper_check, - .atomic_commit = drm_atomic_helper_commit, + .atomic_commit = omap_atomic_commit, };
static int get_connector_type(struct omap_dss_device *dssdev) @@ -521,6 +630,8 @@ static int dev_load(struct drm_device *dev, unsigned long flags) dev->dev_private = priv;
priv->wq = alloc_ordered_workqueue("omapdrm", 0); + init_waitqueue_head(&priv->commit.wait); + spin_lock_init(&priv->commit.lock);
spin_lock_init(&priv->list_lock); INIT_LIST_HEAD(&priv->obj_list); diff --git a/drivers/gpu/drm/omapdrm/omap_drv.h b/drivers/gpu/drm/omapdrm/omap_drv.h index 6448fa809215..21c3929b06e7 100644 --- a/drivers/gpu/drm/omapdrm/omap_drv.h +++ b/drivers/gpu/drm/omapdrm/omap_drv.h @@ -23,6 +23,7 @@ #include <linux/module.h> #include <linux/platform_data/omap_drm.h> #include <linux/types.h> +#include <linux/wait.h> #include <video/omapdss.h>
#include <drm/drmP.h> @@ -105,6 +106,13 @@ struct omap_drm_private { struct list_head irq_list; /* list of omap_drm_irq */ uint32_t vblank_mask; /* irq bits set for userspace vblank */ struct omap_drm_irq error_handler; + + /* atomic commit */ + struct { + wait_queue_head_t wait; + u32 pending; + spinlock_t lock; /* Protects commit.pending */ + } commit; };