[PATCH] drm/amd/display: Reject non-zero src_y and src_x for video planes

[Harry Wentland]

[Why]
This hasn't been well tested and leads to complete system hangs on DCN1
based systems, possibly others.

The system hang can be reproduced by gesturing the video on the YouTube
Android app on ChromeOS into full screen.

[How]
Reject atomic commits with non-zero drm_plane_state.src_x or src_y values.

Signed-off-by: Harry Wentland <harry.wentland at amd.com>
Change-Id: I5e951f95fc87c86517b9ea6e094d73603184f00b
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 4b3b9599aaf7..99fd555ebb91 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2825,6 +2825,13 @@ static int fill_dc_scaling_info(const struct drm_plane_state *state,
 	scaling_info->src_rect.x = state->src_x >> 16;
 	scaling_info->src_rect.y = state->src_y >> 16;
 
+
+	if (state->fb &&
+	    state->fb->format->format == DRM_FORMAT_NV12 &&
+	    (scaling_info->src_rect.x != 0 ||
+	     scaling_info->src_rect.y != 0))
+		return -EINVAL;
+
 	scaling_info->src_rect.width = state->src_w >> 16;
 	if (scaling_info->src_rect.width == 0)
 		return -EINVAL;
-- 
2.31.1