This is a note to let you know that I've just added the patch titled

drm/modeset-lock: Take the modeset BKL for legacy drivers

to the 5.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summ...

The filename of the patch is: drm-modeset-lock-take-the-modeset-bkl-for-legacy-drivers.patch and it can be found in the queue-5.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 77ef38574beb3e0b414db48e9c0f04633df68ba6 Mon Sep 17 00:00:00 2001

From: Daniel Vetter daniel.vetter@intel.com Date: Fri, 14 Aug 2020 11:38:42 +0200 Subject: drm/modeset-lock: Take the modeset BKL for legacy drivers

From: Daniel Vetter daniel.vetter@intel.com

commit 77ef38574beb3e0b414db48e9c0f04633df68ba6 upstream.

This fell off in the conversion in

commit 9bcaa3fe58ab7559e71df798bcff6e0795158695 Author: Michal Orzel michalorzel.eng@gmail.com Date: Tue Apr 28 19:10:04 2020 +0200

drm: Replace drm_modeset_lock/unlock_all with DRM_MODESET_LOCK_ALL_* helpers

but it's caught by the drm_warn_on_modeset_not_all_locked() that the legacy modeset code uses. Since this is the bkl and it's unclear what's all protected, play it safe and grab it again for legacy drivers.

Unfortunately this means we need to sprinkle a few more #includes around.

Also we need to add the drm_device as a parameter to the _END macro.

Finally remove the mute_lock() from setcrtc, since that's now done by the macro.

Cc: Alex Deucher alexdeucher@gmail.com References: https://gitlab.freedesktop.org/drm/amd/-/issues/1224 Fixes: 9bcaa3fe58ab ("drm: Replace drm_modeset_lock/unlock_all with DRM_MODESET_LOCK_ALL_* helpers") Cc: Michal Orzel michalorzel.eng@gmail.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Maxime Ripard mripard@kernel.org Cc: Thomas Zimmermann tzimmermann@suse.de Cc: David Airlie airlied@linux.ie Cc: Daniel Vetter daniel@ffwll.ch Cc: dri-devel@lists.freedesktop.org Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Daniel Vetter daniel.vetter@intel.com Reviewed-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Link: https://patchwork.freedesktop.org/patch/msgid/20200814093842.3048472-1-danie... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/gpu/drm/drm_atomic_helper.c | 7 ++++--- drivers/gpu/drm/drm_color_mgmt.c | 2 +- drivers/gpu/drm/drm_crtc.c | 4 +--- drivers/gpu/drm/drm_mode_object.c | 4 ++-- drivers/gpu/drm/drm_plane.c | 2 +- include/drm/drm_modeset_lock.h | 9 +++++++-- 6 files changed, 16 insertions(+), 12 deletions(-)

--- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -34,6 +34,7 @@ #include <drm/drm_bridge.h> #include <drm/drm_damage_helper.h> #include <drm/drm_device.h> +#include <drm/drm_drv.h> #include <drm/drm_plane_helper.h> #include <drm/drm_print.h> #include <drm/drm_self_refresh_helper.h> @@ -3105,7 +3106,7 @@ void drm_atomic_helper_shutdown(struct d if (ret) DRM_ERROR("Disabling all crtc's during unload failed with %i\n", ret);

- DRM_MODESET_LOCK_ALL_END(ctx, ret); + DRM_MODESET_LOCK_ALL_END(dev, ctx, ret); } EXPORT_SYMBOL(drm_atomic_helper_shutdown);

@@ -3245,7 +3246,7 @@ struct drm_atomic_state *drm_atomic_help }

unlock: - DRM_MODESET_LOCK_ALL_END(ctx, err); + DRM_MODESET_LOCK_ALL_END(dev, ctx, err); if (err) return ERR_PTR(err);

@@ -3326,7 +3327,7 @@ int drm_atomic_helper_resume(struct drm_

err = drm_atomic_helper_commit_duplicated_state(state, &ctx);

- DRM_MODESET_LOCK_ALL_END(ctx, err); + DRM_MODESET_LOCK_ALL_END(dev, ctx, err); drm_atomic_state_put(state);

return err; --- a/drivers/gpu/drm/drm_color_mgmt.c +++ b/drivers/gpu/drm/drm_color_mgmt.c @@ -294,7 +294,7 @@ int drm_mode_gamma_set_ioctl(struct drm_ crtc->gamma_size, &ctx);

out: - DRM_MODESET_LOCK_ALL_END(ctx, ret); + DRM_MODESET_LOCK_ALL_END(dev, ctx, ret); return ret;

} --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -561,7 +561,6 @@ int drm_mode_setcrtc(struct drm_device * if (crtc_req->mode_valid && !drm_lease_held(file_priv, plane->base.id)) return -EACCES;

- mutex_lock(&crtc->dev->mode_config.mutex); DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE, ret);

@@ -728,8 +727,7 @@ out: fb = NULL; mode = NULL;

- DRM_MODESET_LOCK_ALL_END(ctx, ret); - mutex_unlock(&crtc->dev->mode_config.mutex); + DRM_MODESET_LOCK_ALL_END(dev, ctx, ret);

return ret; } --- a/drivers/gpu/drm/drm_mode_object.c +++ b/drivers/gpu/drm/drm_mode_object.c @@ -428,7 +428,7 @@ int drm_mode_obj_get_properties_ioctl(st out_unref: drm_mode_object_put(obj); out: - DRM_MODESET_LOCK_ALL_END(ctx, ret); + DRM_MODESET_LOCK_ALL_END(dev, ctx, ret); return ret; }

@@ -470,7 +470,7 @@ static int set_property_legacy(struct dr break; } drm_property_change_valid_put(prop, ref); - DRM_MODESET_LOCK_ALL_END(ctx, ret); + DRM_MODESET_LOCK_ALL_END(dev, ctx, ret);

return ret; } --- a/drivers/gpu/drm/drm_plane.c +++ b/drivers/gpu/drm/drm_plane.c @@ -791,7 +791,7 @@ static int setplane_internal(struct drm_ crtc_x, crtc_y, crtc_w, crtc_h, src_x, src_y, src_w, src_h, &ctx);

- DRM_MODESET_LOCK_ALL_END(ctx, ret); + DRM_MODESET_LOCK_ALL_END(plane->dev, ctx, ret);

return ret; } --- a/include/drm/drm_modeset_lock.h +++ b/include/drm/drm_modeset_lock.h @@ -164,6 +164,8 @@ int drm_modeset_lock_all_ctx(struct drm_ * is 0, so no error checking is necessary */ #define DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx, flags, ret) \ + if (!drm_drv_uses_atomic_modeset(dev)) \ + mutex_lock(&dev->mode_config.mutex); \ drm_modeset_acquire_init(&ctx, flags); \ modeset_lock_retry: \ ret = drm_modeset_lock_all_ctx(dev, &ctx); \ @@ -172,6 +174,7 @@ modeset_lock_retry: \

/** * DRM_MODESET_LOCK_ALL_END - Helper to release and cleanup modeset locks + * @dev: drm device * @ctx: local modeset acquire context, will be dereferenced * @ret: local ret/err/etc variable to track error status * @@ -188,7 +191,7 @@ modeset_lock_retry: \ * to that failure. In both of these cases the code between BEGIN/END will not * be run, so the failure will reflect the inability to grab the locks. */ -#define DRM_MODESET_LOCK_ALL_END(ctx, ret) \ +#define DRM_MODESET_LOCK_ALL_END(dev, ctx, ret) \ modeset_lock_fail: \ if (ret == -EDEADLK) { \ ret = drm_modeset_backoff(&ctx); \ @@ -196,6 +199,8 @@ modeset_lock_fail: \ goto modeset_lock_retry; \ } \ drm_modeset_drop_locks(&ctx); \ - drm_modeset_acquire_fini(&ctx); + drm_modeset_acquire_fini(&ctx); \ + if (!drm_drv_uses_atomic_modeset(dev)) \ + mutex_unlock(&dev->mode_config.mutex);

#endif /* DRM_MODESET_LOCK_H_ */

Patches currently in stable-queue which might be from daniel.vetter@intel.com are

queue-5.8/drm-modeset-lock-take-the-modeset-bkl-for-legacy-drivers.patch