pm_runtime_get_sync will increment pm usage counter even it failed. Forgetting to putting operation will result in reference leak here. Fix it by replacing it with pm_runtime_resume_and_get to keep usage counter balanced.
Reported-by: Hulk Robot hulkci@huawei.com Signed-off-by: Yu Kuai yukuai3@huawei.com --- drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c index 0cd8f40fb690..305489d48c16 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c @@ -2478,7 +2478,7 @@ static int cdns_mhdp_probe(struct platform_device *pdev) clk_prepare_enable(clk);
pm_runtime_enable(dev); - ret = pm_runtime_get_sync(dev); + ret = pm_runtime_resume_and_get(dev); if (ret < 0) { dev_err(dev, "pm_runtime_get_sync failed\n"); pm_runtime_disable(dev);
Hey Yu,
On Mon, 17 May 2021 at 10:08, Yu Kuai yukuai3@huawei.com wrote:
pm_runtime_get_sync will increment pm usage counter even it failed. Forgetting to putting operation will result in reference leak here. Fix it by replacing it with pm_runtime_resume_and_get to keep usage counter balanced.
Reported-by: Hulk Robot hulkci@huawei.com Signed-off-by: Yu Kuai yukuai3@huawei.com
drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c index 0cd8f40fb690..305489d48c16 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c @@ -2478,7 +2478,7 @@ static int cdns_mhdp_probe(struct platform_device *pdev) clk_prepare_enable(clk);
pm_runtime_enable(dev);
ret = pm_runtime_get_sync(dev);
ret = pm_runtime_resume_and_get(dev); if (ret < 0) { dev_err(dev, "pm_runtime_get_sync failed\n"); pm_runtime_disable(dev);
The code is correct as it is. If pm_runtime_get_sync() fails and increments[1] the pm.usage_count variable, that isn't a problem since pm_runtime_disable() disables pm, and resets pm.usage_count variable to zero[2].
[1] https://elixir.bootlin.com/linux/latest/source/include/linux/pm_runtime.h#L3... [2] https://elixir.bootlin.com/linux/latest/source/drivers/base/power/runtime.c#...
On 2021/05/17 17:27, Robert Foss wrote:
Hey Yu,
On Mon, 17 May 2021 at 10:08, Yu Kuai yukuai3@huawei.com wrote:
pm_runtime_get_sync will increment pm usage counter even it failed. Forgetting to putting operation will result in reference leak here. Fix it by replacing it with pm_runtime_resume_and_get to keep usage counter balanced.
Reported-by: Hulk Robot hulkci@huawei.com Signed-off-by: Yu Kuai yukuai3@huawei.com
drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c index 0cd8f40fb690..305489d48c16 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c @@ -2478,7 +2478,7 @@ static int cdns_mhdp_probe(struct platform_device *pdev) clk_prepare_enable(clk);
pm_runtime_enable(dev);
ret = pm_runtime_get_sync(dev);
ret = pm_runtime_resume_and_get(dev); if (ret < 0) { dev_err(dev, "pm_runtime_get_sync failed\n"); pm_runtime_disable(dev);The code is correct as it is. If pm_runtime_get_sync() fails and increments[1] the pm.usage_count variable, that isn't a problem since pm_runtime_disable() disables pm, and resets pm.usage_count variable to zero[2].
[1] https://elixir.bootlin.com/linux/latest/source/include/linux/pm_runtime.h#L3... [2] https://elixir.bootlin.com/linux/latest/source/drivers/base/power/runtime.c#... .
Hi,
Thank you very much for your explanation
Yu Kuai
On Mon, May 17, 2021 at 11:27:38AM +0200, Robert Foss wrote:
Hey Yu,
On Mon, 17 May 2021 at 10:08, Yu Kuai yukuai3@huawei.com wrote:
pm_runtime_get_sync will increment pm usage counter even it failed. Forgetting to putting operation will result in reference leak here. Fix it by replacing it with pm_runtime_resume_and_get to keep usage counter balanced.
Reported-by: Hulk Robot hulkci@huawei.com Signed-off-by: Yu Kuai yukuai3@huawei.com
drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c index 0cd8f40fb690..305489d48c16 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c @@ -2478,7 +2478,7 @@ static int cdns_mhdp_probe(struct platform_device *pdev) clk_prepare_enable(clk);
pm_runtime_enable(dev);
ret = pm_runtime_get_sync(dev);
ret = pm_runtime_resume_and_get(dev); if (ret < 0) { dev_err(dev, "pm_runtime_get_sync failed\n"); pm_runtime_disable(dev);The code is correct as it is. If pm_runtime_get_sync() fails and increments[1] the pm.usage_count variable, that isn't a problem since pm_runtime_disable() disables pm, and resets pm.usage_count variable to zero[2].
No it doesn't; pm_runtime_disable() does not reset the counter and you still need to decrement the usage count when pm_runtime_get_sync() fails.
[1] https://elixir.bootlin.com/linux/latest/source/include/linux/pm_runtime.h#L3... [2] https://elixir.bootlin.com/linux/latest/source/drivers/base/power/runtime.c#...
Johan
On Tue, 18 May 2021 at 09:42, Johan Hovold johan@kernel.org wrote:
On Mon, May 17, 2021 at 11:27:38AM +0200, Robert Foss wrote:
Hey Yu,
On Mon, 17 May 2021 at 10:08, Yu Kuai yukuai3@huawei.com wrote:
pm_runtime_get_sync will increment pm usage counter even it failed. Forgetting to putting operation will result in reference leak here. Fix it by replacing it with pm_runtime_resume_and_get to keep usage counter balanced.
Reported-by: Hulk Robot hulkci@huawei.com Signed-off-by: Yu Kuai yukuai3@huawei.com
drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c index 0cd8f40fb690..305489d48c16 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c @@ -2478,7 +2478,7 @@ static int cdns_mhdp_probe(struct platform_device *pdev) clk_prepare_enable(clk);
pm_runtime_enable(dev);
ret = pm_runtime_get_sync(dev);
ret = pm_runtime_resume_and_get(dev); if (ret < 0) { dev_err(dev, "pm_runtime_get_sync failed\n");
This error message is a bit confusing now, could you update it.
pm_runtime_disable(dev);The code is correct as it is. If pm_runtime_get_sync() fails and increments[1] the pm.usage_count variable, that isn't a problem since pm_runtime_disable() disables pm, and resets pm.usage_count variable to zero[2].
No it doesn't; pm_runtime_disable() does not reset the counter and you still need to decrement the usage count when pm_runtime_get_sync() fails.
Thanks for chiming in Johan, you're absolutely right and I must have misread something.
With the above fix, feel free to add my r-b.
Reviewed-by: Robert Foss robert.foss@linaro.org
ping ...
On 2021/05/18 20:58, Robert Foss wrote:
On Tue, 18 May 2021 at 09:42, Johan Hovold johan@kernel.org wrote:
On Mon, May 17, 2021 at 11:27:38AM +0200, Robert Foss wrote:
Hey Yu,
On Mon, 17 May 2021 at 10:08, Yu Kuai yukuai3@huawei.com wrote:
pm_runtime_get_sync will increment pm usage counter even it failed. Forgetting to putting operation will result in reference leak here. Fix it by replacing it with pm_runtime_resume_and_get to keep usage counter balanced.
Reported-by: Hulk Robot hulkci@huawei.com Signed-off-by: Yu Kuai yukuai3@huawei.com
drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c index 0cd8f40fb690..305489d48c16 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c @@ -2478,7 +2478,7 @@ static int cdns_mhdp_probe(struct platform_device *pdev) clk_prepare_enable(clk);
pm_runtime_enable(dev);
ret = pm_runtime_get_sync(dev);
ret = pm_runtime_resume_and_get(dev); if (ret < 0) { dev_err(dev, "pm_runtime_get_sync failed\n");This error message is a bit confusing now, could you update it.
pm_runtime_disable(dev);The code is correct as it is. If pm_runtime_get_sync() fails and increments[1] the pm.usage_count variable, that isn't a problem since pm_runtime_disable() disables pm, and resets pm.usage_count variable to zero[2].
No it doesn't; pm_runtime_disable() does not reset the counter and you still need to decrement the usage count when pm_runtime_get_sync() fails.
Thanks for chiming in Johan, you're absolutely right and I must have misread something.
With the above fix, feel free to add my r-b.
Reviewed-by: Robert Foss robert.foss@linaro.org .
pm_runtime_get_sync will increment pm usage counter even it failed. Forgetting to putting operation will result in reference leak here. Fix it by replacing it with pm_runtime_resume_and_get to keep usage counter balanced.
Reported-by: Hulk Robot hulkci@huawei.com Signed-off-by: Yu Kuai yukuai3@huawei.com --- changes in V2: - change error message.
drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c index 0cd8f40fb690..eab959a59214 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c @@ -2478,9 +2478,9 @@ static int cdns_mhdp_probe(struct platform_device *pdev) clk_prepare_enable(clk);
pm_runtime_enable(dev); - ret = pm_runtime_get_sync(dev); + ret = pm_runtime_resume_and_get(dev); if (ret < 0) { - dev_err(dev, "pm_runtime_get_sync failed\n"); + dev_err(dev, "pm_runtime_resume_and_get failed\n"); pm_runtime_disable(dev); goto clk_disable; }
Hey Yu,
I'm not finding your this patch with the correct tags. I'd expect the subject: [PATCH v2] drm: bridge: cdns-mhdp8546: Fix PM reference leak in cdns_mhdp_probe()
Can you please resubmit using this title, just to be sure I merge the right version of this code.
On Sat, 29 May 2021 at 11:46, Yu Kuai yukuai3@huawei.com wrote:
pm_runtime_get_sync will increment pm usage counter even it failed. Forgetting to putting operation will result in reference leak here. Fix it by replacing it with pm_runtime_resume_and_get to keep usage counter balanced.
Reported-by: Hulk Robot hulkci@huawei.com Signed-off-by: Yu Kuai yukuai3@huawei.com
changes in V2:
- change error message.
drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c index 0cd8f40fb690..eab959a59214 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c @@ -2478,9 +2478,9 @@ static int cdns_mhdp_probe(struct platform_device *pdev) clk_prepare_enable(clk);
pm_runtime_enable(dev);
ret = pm_runtime_get_sync(dev);
ret = pm_runtime_resume_and_get(dev); if (ret < 0) {
dev_err(dev, "pm_runtime_get_sync failed\n");
dev_err(dev, "pm_runtime_resume_and_get failed\n"); pm_runtime_disable(dev); goto clk_disable; }-- 2.25.4
On 2021/05/31 18:54, Robert Foss wrote:
Hey Yu,
I'm not finding your this patch with the correct tags. I'd expect the subject: [PATCH v2] drm: bridge: cdns-mhdp8546: Fix PM reference leak in cdns_mhdp_probe()
Can you please resubmit using this title, just to be sure I merge the right version of this code.
Hi,
I just resubmit v2 patch.
Thanks Yu Kuai
On Sat, 29 May 2021 at 11:46, Yu Kuai yukuai3@huawei.com wrote:
pm_runtime_get_sync will increment pm usage counter even it failed. Forgetting to putting operation will result in reference leak here. Fix it by replacing it with pm_runtime_resume_and_get to keep usage counter balanced.
Reported-by: Hulk Robot hulkci@huawei.com Signed-off-by: Yu Kuai yukuai3@huawei.com
changes in V2:
- change error message.
drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c index 0cd8f40fb690..eab959a59214 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c @@ -2478,9 +2478,9 @@ static int cdns_mhdp_probe(struct platform_device *pdev) clk_prepare_enable(clk);
pm_runtime_enable(dev);
ret = pm_runtime_get_sync(dev);
ret = pm_runtime_resume_and_get(dev); if (ret < 0) {
dev_err(dev, "pm_runtime_get_sync failed\n");
dev_err(dev, "pm_runtime_resume_and_get failed\n"); pm_runtime_disable(dev); goto clk_disable; }-- 2.25.4
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