[PATCH] drm: add docs about the IN_FORMATS plane property

[Simon Ser]

This is a standard property attached to planes in drm_universal_plane_init
when drm_mode_config.allow_fb_modifiers is true.

Signed-off-by: Simon Ser <contact at emersion.fr>
Cc: Daniel Vetter <daniel at ffwll.ch>
Cc: Daniel Stone <daniel at fooishbar.org>
---
 drivers/gpu/drm/drm_blend.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/drm_blend.c b/drivers/gpu/drm/drm_blend.c
index 121481f6aa71..88eedee018d3 100644
--- a/drivers/gpu/drm/drm_blend.c
+++ b/drivers/gpu/drm/drm_blend.c
@@ -183,6 +183,12 @@
  *		 plane does not expose the "alpha" property, then this is
  *		 assumed to be 1.0
  *
+ * IN_FORMATS:
+ *	Blob property which contains the set of buffer format and modifier
+ *	pairs supported by this plane. The blob is a drm_format_modifier_blob
+ *	struct. Without this property the plane doesn't support buffers with
+ *	modifiers. Userspace cannot change this property.
+ *
  * Note that all the property extensions described here apply either to the
  * plane or the CRTC (e.g. for the background color, which currently is not
  * exposed and assumed to be black).
-- 
2.26.0