[PATCH AUTOSEL 4.9 12/26] drm/amdgpu/display: fix ref count leak when pm_runtime_get_sync fails

From: Sasha Levin
Date: Fri Aug 21 2020 - 12:44:03 EST


From: Navid Emamdoost <navid.emamdoost@xxxxxxxxx>

[ Upstream commit f79f94765f8c39db0b7dec1d335ab046aac03f20 ]

The call to pm_runtime_get_sync increments the counter even in case of
failure, leading to incorrect ref count.
In case of failure, decrement the ref count before returning.

Signed-off-by: Navid Emamdoost <navid.emamdoost@xxxxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
index e9311eb7b8d9f..694f631d9c90d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
@@ -734,8 +734,10 @@ amdgpu_connector_lvds_detect(struct drm_connector *connector, bool force)

if (!drm_kms_helper_is_poll_worker()) {
r = pm_runtime_get_sync(connector->dev->dev);
- if (r < 0)
+ if (r < 0) {
+ pm_runtime_put_autosuspend(connector->dev->dev);
return connector_status_disconnected;
+ }
}

if (encoder) {
@@ -872,8 +874,10 @@ amdgpu_connector_vga_detect(struct drm_connector *connector, bool force)

if (!drm_kms_helper_is_poll_worker()) {
r = pm_runtime_get_sync(connector->dev->dev);
- if (r < 0)
+ if (r < 0) {
+ pm_runtime_put_autosuspend(connector->dev->dev);
return connector_status_disconnected;
+ }
}

encoder = amdgpu_connector_best_single_encoder(connector);
@@ -996,8 +1000,10 @@ amdgpu_connector_dvi_detect(struct drm_connector *connector, bool force)

if (!drm_kms_helper_is_poll_worker()) {
r = pm_runtime_get_sync(connector->dev->dev);
- if (r < 0)
+ if (r < 0) {
+ pm_runtime_put_autosuspend(connector->dev->dev);
return connector_status_disconnected;
+ }
}

if (!force && amdgpu_connector_check_hpd_status_unchanged(connector)) {
@@ -1371,8 +1377,10 @@ amdgpu_connector_dp_detect(struct drm_connector *connector, bool force)

if (!drm_kms_helper_is_poll_worker()) {
r = pm_runtime_get_sync(connector->dev->dev);
- if (r < 0)
+ if (r < 0) {
+ pm_runtime_put_autosuspend(connector->dev->dev);
return connector_status_disconnected;
+ }
}

if (!force && amdgpu_connector_check_hpd_status_unchanged(connector)) {
--
2.25.1