From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
We don't have proper sub-pixel coordinate support (some platforms
simply can't do it, for others we've not implemented it). This
can cause us to treat a < 1 pixel source width/height as zero
which is not valid for the hardware, and can also cause a div
by zero in some cases.
Refuse < 1x1 plane source size to avoid these problems.
Cc: stable@xxxxxxxxxxxxxxx
Cc: Juha-Pekka Heikkila <juhapekka.heikkila@xxxxxxxxx>
Reported-by: Drew Davenport <ddavenport@xxxxxxxxxxxx>
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
---
The other option would be to clamp the source size to >=1x1 pixels,
but dunno if that has any real benefits.
drivers/gpu/drm/i915/display/intel_atomic_plane.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.c b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
index 10e1fc9d0698..c6e43d684458 100644
--- a/drivers/gpu/drm/i915/display/intel_atomic_plane.c
+++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
@@ -921,6 +921,21 @@ int intel_atomic_plane_check_clipping(struct intel_plane_state *plane_state,
*/
plane_state->uapi.visible = drm_rect_clip_scaled(src, dst, clip);
+ /*
+ * Avoid zero source size when we later
+ * discard the fractional coords.
+ *
+ * FIXME add proper sub-pixel coordinate handling
+ * for platforms/planes that support it.
+ */
+ if (plane_state->uapi.visible &&
+ (drm_rect_width(src) < 0x10000 || drm_rect_height(src) < 0x10000)) {
+ drm_dbg_kms(&i915->drm, "Plane source must be at least 1x1 pixels\n");
+ drm_rect_debug_print("src: ", src, true);
+ drm_rect_debug_print("dst: ", dst, false);
+ return -EINVAL;
+ }
+
drm_rect_rotate_inv(src, fb->width << 16, fb->height << 16, rotation);
if (!can_position && plane_state->uapi.visible &&
--
2.38.2
