[PATCH 5.4 18/60] drm/amd/display: Decrement refcount of dc_sink before reassignment

Greg Kroah-Hartman
2021-02-15T15:59:57Z

From: Victor Lu <victorchengchi.lu@amd.com>

[ Upstream commit 8e92bb0fa75bca9a57e4aba2e36f67d8016a3053 ]

[why]
An old dc_sink state is causing a memory leak because it is missing a
dc_sink_release before a new dc_sink is assigned back to
aconnector->dc_sink.

[how]
Decrement the dc_sink refcount before reassigning it to a new dc_sink.

Signed-off-by: Victor Lu <victorchengchi.lu@amd.com>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
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 | 4 +++-
1 file changed, 3 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 b4da8d1e4fb87..fbbe611d4873f 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1417,8 +1417,10 @@ amdgpu_dm_update_connector_after_detect(struct amdgpu_dm_connector *aconnector)
* TODO: check if we still need the S3 mode update workaround.
* If yes, put it here.
*/
- if (aconnector->dc_sink)
+ if (aconnector->dc_sink) {
amdgpu_dm_update_freesync_caps(connector, NULL);
+ dc_sink_release(aconnector->dc_sink);
+ }

aconnector->dc_sink = sink;
dc_sink_retain(aconnector->dc_sink);
--
2.27.0