If the device is already in a runtime PM enabled state pm_runtime_get_sync() will return 1, so a test for negative value should be used to check for errors.

Also, we need to call pm_runtime_put_noidle() when pm_runtime_get_sync() fails, so use pm_runtime_resume_and_get() instead. this function will handle this.

Fixes: 4078f5757144 ("drm/vc4: Add DSI driver") Signed-off-by: Miaoqian Lin linmq006@gmail.com --- change in v2: - switch to pm_runtime_resume_and_get() to fix refcount leak. --- drivers/gpu/drm/vc4/vc4_dsi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c index 752f921735c6..9d7ffaf6bc70 100644 --- a/drivers/gpu/drm/vc4/vc4_dsi.c +++ b/drivers/gpu/drm/vc4/vc4_dsi.c @@ -846,8 +846,8 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder) unsigned long phy_clock; int ret;

- ret = pm_runtime_get_sync(dev); - if (ret) { + ret = pm_runtime_resume_and_get(dev); + if (ret < 0) { DRM_ERROR("Failed to runtime PM enable on DSI%d\n", dsi->variant->port); return; }

On 2022/4/20 15:51, Maxime Ripard wrote:

On Wed, Apr 20, 2022 at 12:49:48AM +0000, Miaoqian Lin wrote:

...

If the device is already in a runtime PM enabled state pm_runtime_get_sync() will return 1, so a test for negative value should be used to check for errors.

Also, we need to call pm_runtime_put_noidle() when pm_runtime_get_sync() fails, so use pm_runtime_resume_and_get() instead. this function will handle this.

Fixes: 4078f5757144 ("drm/vc4: Add DSI driver") Signed-off-by: Miaoqian Lin linmq006@gmail.com

---

change in v2:

• switch to pm_runtime_resume_and_get() to fix refcount leak.

---

drivers/gpu/drm/vc4/vc4_dsi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c index 752f921735c6..9d7ffaf6bc70 100644 --- a/drivers/gpu/drm/vc4/vc4_dsi.c +++ b/drivers/gpu/drm/vc4/vc4_dsi.c @@ -846,8 +846,8 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder) unsigned long phy_clock; int ret;

• ret = pm_runtime_get_sync(dev);
• if (ret) {

• ret = pm_runtime_resume_and_get(dev);
• if (ret < 0) {

pm_runtime_resume_and_get will return 0 on success, so the previous check was correct

previous check is for pm_runtime_get_sync() not for pm_runtime_resume_and_get (),

I switch to pm_runtime_resume_and_get() to fix the refcount leak bug at the same time.

Sure it's ok to use check if(ret) to check the retval, I just follow a more common way

for usage of pm_runtime_resume_and_get() in the codebase—— check ret<0

Since pm_runtime_resume_and_get() return negative error code.

Maxime

If the device is already in a runtime PM enabled state pm_runtime_get_sync() will return 1.

Also, we need to call pm_runtime_put_noidle() when pm_runtime_get_sync() fails, so use pm_runtime_resume_and_get() instead. this function will handle this.

Fixes: 4078f5757144 ("drm/vc4: Add DSI driver") Signed-off-by: Miaoqian Lin linmq006@gmail.com --- change in v2: - switch to pm_runtime_resume_and_get() to fix refcount leak. changes in v3: - keep the original checking way for retval. --- drivers/gpu/drm/vc4/vc4_dsi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c index 752f921735c6..98308a17e4ed 100644 --- a/drivers/gpu/drm/vc4/vc4_dsi.c +++ b/drivers/gpu/drm/vc4/vc4_dsi.c @@ -846,7 +846,7 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder) unsigned long phy_clock; int ret;

- ret = pm_runtime_get_sync(dev); + ret = pm_runtime_resume_and_get(dev); if (ret) { DRM_ERROR("Failed to runtime PM enable on DSI%d\n", dsi->variant->port); return;