[PATCH 02/23] drm/amd/display: Add debug out when viewport too small

[Solomon Chiu]

From: Nikola Cornij <nikola.cornij at amd.com>

[why] It helps debugging display setup issues

Signed-off-by: Nikola Cornij <nikola.cornij at amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas at amd.com>
Acked-by: Solomon Chiu <solomon.chiu at amd.com>
---
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c    | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 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 2506e85a19b6..7347a3dd66fc 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -6656,13 +6656,17 @@ static int dm_plane_helper_check_state(struct drm_plane_state *state,
 			else if (state->crtc_y + state->crtc_h > new_crtc_state->mode.crtc_vdisplay)
 				viewport_height = new_crtc_state->mode.crtc_vdisplay - state->crtc_y;
 
-			/* If completely outside of screen, viewport_width and/or viewport_height will be negative,
-			 * which is still OK to satisfy the condition below, thereby also covering these cases
-			 * (when plane is completely outside of screen).
-			 * x2 for width is because of pipe-split.
-			 */
-			if (viewport_width < MIN_VIEWPORT_SIZE*2 || viewport_height < MIN_VIEWPORT_SIZE)
+			if (viewport_width < 0 || viewport_height < 0) {
+				DRM_DEBUG_ATOMIC("Plane completely outside of screen\n");
+				return -EINVAL;
+			} else if (viewport_width < MIN_VIEWPORT_SIZE*2) { /* x2 for width is because of pipe-split. */
+				DRM_DEBUG_ATOMIC("Viewport width %d smaller than %d\n", viewport_width, MIN_VIEWPORT_SIZE*2);
+				return -EINVAL;
+			} else if (viewport_height < MIN_VIEWPORT_SIZE) {
+				DRM_DEBUG_ATOMIC("Viewport height %d smaller than %d\n", viewport_height, MIN_VIEWPORT_SIZE);
 				return -EINVAL;
+			}
+
 		}
 
 		/* Get min/max allowed scaling factors from plane caps. */
-- 
2.29.0