drm/amd/display: Guard against null stream_state in set_crc_source

[Why]

The igt@kms_plane@pixel-format-pipe tests can create a sequence where
stream_state is NULL during amdgpu_dm_crtc_set_crc_source which results
in a null pointer dereference.

[How]

Guard against stream_state being NULL before accessing its fields. This
doesn't fix the root cause of the issue so a DRM_ERROR is generated
to still fail the tests.

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: David Francis <David.Francis@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crc.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crc.c
index 01fc5717b657fb73ecb5b5d41ca03d511ba358a3..f088ac58597803d3c257ccdeaea656eb0dfd723f 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crc.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crc.c
@@ -75,6 +75,11 @@ int amdgpu_dm_crtc_set_crc_source(struct drm_crtc *crtc, const char *src_name)
                return -EINVAL;
        }
 
+       if (!stream_state) {
+               DRM_ERROR("No stream state for CRTC%d\n", crtc->index);
+               return -EINVAL;
+       }
+
        /* When enabling CRC, we should also disable dithering. */
        if (source == AMDGPU_DM_PIPE_CRC_SOURCE_AUTO) {
                if (dc_stream_configure_crc(stream_state->ctx->dc,