gpu/drm/drm_plane.c

1527  * DOC: damage tracking
1530  * specify a list of damage rectangles on a plane in framebuffer coordinates of
1531  * the framebuffer attached to the plane. In current context damage is the area
1541  * ignore damage clips property and in that case driver will do a full plane
1542  * update. In case damage clips are provided then it is guaranteed that the area
1543  * inside damage clips will be updated to plane. For efficiency driver can do
1544  * full update or can update more than specified in damage clips. Since driver
1547  * provides damage clips which doesn't encompass the actual damage to
1552  * damage clips are not in 16.16 fixed point. Similar to plane src in
1553  * framebuffer, damage clips cannot be negative. In damage clip, x1/y1 are
1555  * damage clips, it is strongly discouraged.
1557  * Drivers that are interested in damage interface for plane should enable
1559  * Drivers implementing damage can use drm_atomic_helper_damage_iter_init() and
1560  * drm_atomic_helper_damage_iter_next() helper iterator function to get damage
1563  * Note that there are two types of damage handling: frame damage and buffer
1564  * damage, the type of damage handling implemented depends on a driver's upload
1566  * handle frame damage, while drivers implementing a per-buffer upload target
1567  * need to handle buffer damage.
1569  * The existing damage helpers only support the frame damage type, there is no
1570  * buffer age support or similar damage accumulation algorithm implemented yet.
1572  * Only drivers handling frame damage can use the mentioned damage helpers to
1573  * iterate over the damaged regions. Drivers that handle buffer damage, must set
1575  * to know that damage clips should be ignored and return &drm_plane_state.src
1576  * as the damage rectangle, to force a full plane update.
1586  * can be improved in the future if support for frame damage is added to the DRM
1587  * damage helpers, similarly to how user-space already handle this case as it is
1591  *     https://emersion.fr/blog/2019/intro-to-damage-tracking/
1595  * drm_plane_enable_fb_damage_clips - Enables plane fb damage clips property.
1596  * @plane: Plane on which to enable damage clips property.
1598  * This function lets driver to enable the damage clips property on a plane.
1611  * drm_plane_get_damage_clips_count - Returns damage clips count.
1635  * drm_plane_get_damage_clips - Returns damage clips.
1641  * the driver can only handle a single damage region at most.
1643  * Return: Damage clips in plane fb_damage_clips blob property.