Commit 7a235125 authored by Nicholas Kazlauskas's avatar Nicholas Kazlauskas Committed by Alex Deucher
Browse files

drm/amd/display: Check return code for CRC drm_crtc_vblank_get 



[Why]
The call to drm_crtc_vblank_get can fail if vblank is disabled and
we try to increment the reference.

Since drm_crtc_vblank_get internally drops the reference when it fails
it means the subsequent drm_crtc_vblank_put(...) when closing the file
drops a zero reference.

This was found via igt@kms_plane@pixel-format-pipe-A-planes.

[How]
Check the return code and return it on failure.

We wouldn't have been able to enable CRC reading anyway since vblank
wasn't enabled.

Signed-off-by: default avatarNicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: default avatarDavid Francis <David.Francis@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 6da6c279

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crc.c

+5 −1
Original line number Diff line number Diff line
@@ -106,6 +106,7 @@ int amdgpu_dm_crtc_set_crc_source(struct drm_crtc *crtc, const char *src_name) 
	struct drm_dp_aux *aux = NULL;

	bool enable = false;

	bool enabled = false;

	int ret;



	enum amdgpu_dm_pipe_crc_source source = dm_parse_crc_source(src_name);
@@ -176,7 +177,10 @@ int amdgpu_dm_crtc_set_crc_source(struct drm_crtc *crtc, const char *src_name) 
	 */

	enabled = amdgpu_dm_is_valid_crc_source(crtc_state->crc_src);

	if (!enabled && enable) {

		drm_crtc_vblank_get(crtc);

		ret = drm_crtc_vblank_get(crtc);

		if (ret)

			return ret;



		if (dm_is_crc_source_dprx(source)) {

			if (drm_dp_start_crc(aux, crtc)) {

				DRM_DEBUG_DRIVER("dp start crc failed\n");