DC's enum surface_pixel_format has no RGBA8888 (memory order A,B,G,R):
fill_dc_plane_info_and_addr() has no case for it and returns -EINVAL.
Yet rgb_formats[] and overlay_formats[] advertise DRM_FORMAT_RGBA8888, so
compositors (KWin on Wayland) pick it for layers with alpha and every
atomic commit fails once per frame, flooding dmesg with

  amdgpu 0000:06:00.0: [drm] *ERROR* Unsupported screen format RA24
  little-endian (0x34324152)

and forcing a fallback to composition on every frame.

Remove the two entries.  No working configuration is lost: a plane that
advertises RGBA8888 can never convert it in fill_dc_plane_info_and_addr(),
on any display generation.

Tested on Raphael 610M (DCN 3.1.5): before, ~240 atomic commits per second
failed with -EINVAL; after, the plane format list no longer contains RA24
and dmesg is clean.

Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/5339
Signed-off-by: MuXian Chen <[email protected]>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c 
b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
index 9139823..6d5454f 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
@@ -49,11 +49,13 @@
  * For future use cases we should either initialize them dynamically based on
  * plane capabilities, or initialize this array to all formats, so internal drm
  * check will succeed, and let DC implement proper check
+ *
+ * DC has no surface format for DRM_FORMAT_RGBA8888, so it must not be
+ * advertised here or in overlay_formats.
  */
 static const uint32_t rgb_formats[] = {
        DRM_FORMAT_XRGB8888,
        DRM_FORMAT_ARGB8888,
-       DRM_FORMAT_RGBA8888,
        DRM_FORMAT_XRGB2101010,
        DRM_FORMAT_XBGR2101010,
        DRM_FORMAT_ARGB2101010,
@@ -70,7 +72,6 @@ static const uint32_t rgb_formats[] = {
 static const uint32_t overlay_formats[] = {
        DRM_FORMAT_XRGB8888,
        DRM_FORMAT_ARGB8888,
-       DRM_FORMAT_RGBA8888,
        DRM_FORMAT_XBGR8888,
        DRM_FORMAT_ABGR8888,
        DRM_FORMAT_RGB565,
-- 
2.56.0

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