Hello Leo Li,
Commit 4caacd1671b7 ("drm/amd/display: Do not elevate mem_type change
to full update") from Dec 11, 2024 (linux-next), leads to the
following Smatch static checker warning:
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:11486 amdgpu_dm_crtc_mem_type_changed()
error: 'new_plane_state' dereferencing possible ERR_PTR()
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c
11475 static bool amdgpu_dm_crtc_mem_type_changed(struct drm_device *dev,
11476 struct drm_atomic_state *state,
11477 struct drm_crtc_state *crtc_state)
11478 {
11479 struct drm_plane *plane;
11480 struct drm_plane_state *new_plane_state, *old_plane_state;
11481
11482 drm_for_each_plane_mask(plane, dev, crtc_state->plane_mask) {
11483 new_plane_state = drm_atomic_get_plane_state(state, plane);
11484 old_plane_state = drm_atomic_get_plane_state(state, plane);
^^^^^^^^^^^^^^^^^^^^^^^^^^
These functions can fail.
11485
--> 11486 if (old_plane_state->fb && new_plane_state->fb &&
11487 get_mem_type(old_plane_state->fb) != get_mem_type(new_plane_state->fb))
11488 return true;
11489 }
11490
11491 return false;
11492 }
regards,
dan carpenter
