[PATCH AUTOSEL 5.6 035/606] drm/amd/display: add basic atomic check for cursor plane

Sasha Levin
2020-06-09T00:40:53Z

From: Simon Ser <contact@emersion.fr>

commit 626bf90fe03fa080d8df06bb0397c95c53ae8e27 upstream.

This patch adds a basic cursor check when an atomic test-only commit is
performed. The position and size of the cursor plane is checked.

This should fix user-space relying on atomic checks to assign buffers to
planes.

Signed-off-by: Simon Ser <contact@emersion.fr>
Reported-by: Roman Gilg <subdiff@gmail.com>
References: https://github.com/emersion/libliftoff/issues/46
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Harry Wentland <hwentlan@amd.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 26 +++++++++++++++++--
1 file changed, 24 insertions(+), 2 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 8136a58deb39..5e27a67fbc58 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -7716,6 +7716,7 @@ static int dm_update_plane_state(struct dc *dc,
struct drm_crtc_state *old_crtc_state, *new_crtc_state;
struct dm_crtc_state *dm_new_crtc_state, *dm_old_crtc_state;
struct dm_plane_state *dm_new_plane_state, *dm_old_plane_state;
+ struct amdgpu_crtc *new_acrtc;
bool needs_reset;
int ret = 0;

@@ -7725,9 +7726,30 @@ static int dm_update_plane_state(struct dc *dc,
dm_new_plane_state = to_dm_plane_state(new_plane_state);
dm_old_plane_state = to_dm_plane_state(old_plane_state);

- /*TODO Implement atomic check for cursor plane */
- if (plane->type == DRM_PLANE_TYPE_CURSOR)
+ /*TODO Implement better atomic check for cursor plane */
+ if (plane->type == DRM_PLANE_TYPE_CURSOR) {
+ if (!enable || !new_plane_crtc ||
+ drm_atomic_plane_disabling(plane->state, new_plane_state))
+ return 0;
+
+ new_acrtc = to_amdgpu_crtc(new_plane_crtc);
+
+ if ((new_plane_state->crtc_w > new_acrtc->max_cursor_width) ||
+ (new_plane_state->crtc_h > new_acrtc->max_cursor_height)) {
+ DRM_DEBUG_ATOMIC("Bad cursor size %d x %d\n",
+ new_plane_state->crtc_w, new_plane_state->crtc_h);
+ return -EINVAL;
+ }
+
+ if (new_plane_state->crtc_x <= -new_acrtc->max_cursor_width ||
+ new_plane_state->crtc_y <= -new_acrtc->max_cursor_height) {
+ DRM_DEBUG_ATOMIC("Bad cursor position %d, %d\n",
+ new_plane_state->crtc_x, new_plane_state->crtc_y);
+ return -EINVAL;
+ }
+
return 0;
+ }

needs_reset = should_reset_plane(state, plane, old_plane_state,
new_plane_state);
--
2.25.1