Merge tag 'drm-misc-next-2021-01-06' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

drm-misc-next for v5.12:

Core Changes:
- Lots of drm documentation updates by Simor Ser.
- Require that each crtc has a unique primary plane.
- Add fixme that fbdev_generic_setup is confusing.

Driver Changes:
- Update addresses for TI display drivers maintainers.
- Make DRM_VIRTIO_GPU select VIRTIO.
- Small fixes to qxl, virtio, hisilicon, tve200, panel/s6e63m0.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/fdfbfd7a-b91d-3f59-11c8-984704ce0ee1@linux.intel.com

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
index de75c9f092b7..bf6e525bb116 100644
--- a/drivers/gpu/drm/drm_plane.c
+++ b/drivers/gpu/drm/drm_plane.c
@@ -55,6 +55,12 @@
  * enum drm_plane_type). A plane can be compatible with multiple CRTCs, see
  * &drm_plane.possible_crtcs.
  *
+ * Each CRTC must have a unique primary plane userspace can attach to enable
+ * the CRTC. In other words, userspace must be able to attach a different
+ * primary plane to each CRTC at the same time. Primary planes can still be
+ * compatible with multiple CRTCs. There must be exactly as many primary planes
+ * as there are CRTCs.
+ *
  * Legacy uAPI doesn't expose the primary and cursor planes directly. DRM core
  * relies on the driver to set the primary and optionally the cursor plane used
  * for legacy IOCTLs. This is done by calling drm_crtc_init_with_planes(). All
@@ -62,6 +68,18 @@
  * userspace too much.
  */
 
+/**
+ * DOC: standard plane properties
+ *
+ * DRM planes have a few standardized properties:
+ *
+ * IN_FORMATS:
+ *     Blob property which contains the set of buffer format and modifier
+ *     pairs supported by this plane. The blob is a struct
+ *     drm_format_modifier_blob. Without this property the plane doesn't
+ *     support buffers with modifiers. Userspace cannot change this property.
+ */
+
 static unsigned int drm_num_planes(struct drm_device *dev)
 {
 	unsigned int num = 0;