From 7a235125959cffa28c20059ff1cb8725571fcf9f Mon Sep 17 00:00:00 2001 From: Nicholas Kazlauskas Date: Tue, 20 Aug 2019 12:58:37 -0400 Subject: [PATCH] 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: Nicholas Kazlauskas Reviewed-by: David Francis Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crc.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) 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 365aaef3ecaf..eb114e377233 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crc.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crc.c @@ -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"); -- 2.30.2