[PATCH] drm/amd/display: Make underlay rules less strict

[Rodrigo Siqueira]

Currently, we reject all conditions where the underlay plane goes
outside the overlay plane limits, which is not entirely correct since we
reject some valid cases like the ones illustrated below:

  +--------------------+  +--------------------+
  |   Overlay plane    |  |   Overlay plane    |
  |                    |  |        +-----------|--+
  | +--------------+   |  |        |           |  |
  | |              |   |  |        |           |  |
  +--------------------+  +--------------------+  |
    | Primary plane|               +--------------+
    |  (underlay)  |
    +--------------+
  +-+--------------+---+  +--------------------+
  |    Overlay plane   |  |    Overlay plane   |
+-|------------+       |  |       +--------------+
| |            |       |  |       |            | |
| |            |       |  |       |            | |
| |            |       |  |       |            | |
+-|------------+       |  |       +--------------+
  +--------------------+  +--------------------+

This patch fixes this issue by only rejecting commit requests where the
underlay is entirely outside the overlay limits. After applying this
patch, a set of subtests related to kms_plane, kms_plane_alpha_blend,
and kms_plane_scaling will pass.

Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira at amd.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

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 cc048c348a92..15006aafc630 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -10098,10 +10098,10 @@ static int validate_overlay(struct drm_atomic_state *state)
 		return 0;
 
 	/* Perform the bounds check to ensure the overlay plane covers the primary */
-	if (primary_state->crtc_x < overlay_state->crtc_x ||
-	    primary_state->crtc_y < overlay_state->crtc_y ||
-	    primary_state->crtc_x + primary_state->crtc_w > overlay_state->crtc_x + overlay_state->crtc_w ||
-	    primary_state->crtc_y + primary_state->crtc_h > overlay_state->crtc_y + overlay_state->crtc_h) {
+	if (primary_state->crtc_x + primary_state->crtc_w < overlay_state->crtc_x ||
+	    primary_state->crtc_x > overlay_state->crtc_x + overlay_state->crtc_w ||
+	    primary_state->crtc_y > overlay_state->crtc_y + overlay_state->crtc_h ||
+	    primary_state->crtc_y + primary_state->crtc_h < overlay_state->crtc_y) {
 		DRM_DEBUG_ATOMIC("Overlay plane is enabled with hardware cursor but does not fully cover primary plane\n");
 		return -EINVAL;
 	}
-- 
2.25.1