[PATCH 5.11 362/601] drm/amd/display: check fb of primary plane

Greg Kroah-Hartman
2021-05-12T17:39:25Z

From: Sefa Eyeoglu <contact@scrumplex.net>

[ Upstream commit 7df4ceb60fa9a3c5160cfd5b696657291934a2c9 ]

Sometimes the primary plane might not be initialized (yet), which
causes dm_check_crtc_cursor to divide by zero.
Apparently a weird state before a S3-suspend causes the aforementioned
divide-by-zero error when resuming from S3. This was explained in
bug 212293 on Bugzilla.

To avoid this divide-by-zero error we check if the primary plane's fb
isn't NULL. If it's NULL the src_w and src_h attributes will be 0,
which would cause a divide-by-zero.

This fixes Bugzilla report 212293
Bug: https://bugzilla.kernel.org/show_bug.cgi?id=212293

Fixes: 12f4849a1cfd69f3 ("drm/amd/display: check cursor scaling")
Reviewed-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Sefa Eyeoglu <contact@scrumplex.net>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

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 d7d2cf8b53f4..36898ae63f30 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -9119,7 +9119,8 @@ static int dm_check_crtc_cursor(struct drm_atomic_state *state,

new_cursor_state = drm_atomic_get_new_plane_state(state, crtc->cursor);
new_primary_state = drm_atomic_get_new_plane_state(state, crtc->primary);
- if (!new_cursor_state || !new_primary_state || !new_cursor_state->fb) {
+ if (!new_cursor_state || !new_primary_state ||
+ !new_cursor_state->fb || !new_primary_state->fb) {
return 0;
}

--
2.30.2