| Message ID | 20200523100332.32626-1-dinghao.liu@zju.edu.cn (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | media: coda: Fix runtime PM imbalance in coda_probe | expand |
Hi Dinghao, thank you for the patch! The first part is fine, but I think the second part is not necessary, see below: On Sat, May 23, 2020 at 06:03:32PM +0800, Dinghao Liu wrote: > When coda_firmware_request() returns an error code, > a pairing runtime PM usage counter decrement is needed > to keep the counter balanced. > > Also, the caller expects coda_probe() to increase PM > usage counter, there should be a refcount decrement > in coda_remove() to keep the counter balanced. coda_probe() increments the usage counter only until coda_fw_callback() decrements it again. Where is the imbalance? > Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> > --- > drivers/media/platform/coda/coda-common.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/media/platform/coda/coda-common.c b/drivers/media/platform/coda/coda-common.c > index d0d093dd8f7c..550e9a1266da 100644 > --- a/drivers/media/platform/coda/coda-common.c > +++ b/drivers/media/platform/coda/coda-common.c > @@ -3119,6 +3119,8 @@ static int coda_probe(struct platform_device *pdev) > return 0; > > err_alloc_workqueue: > + pm_runtime_disable(&pdev->dev); > + pm_runtime_put_noidle(&pdev->dev); These seem right, they balance out the pm_runtime_enable() and pm_runtime_get_noresume() right before the error. > destroy_workqueue(dev->workqueue); > err_v4l2_register: > v4l2_device_unregister(&dev->v4l2_dev); > @@ -3136,6 +3138,7 @@ static int coda_remove(struct platform_device *pdev) > } > if (dev->m2m_dev) > v4l2_m2m_release(dev->m2m_dev); > + pm_runtime_put_noidle(&pdev->dev); I think this is incorrect. There is one pm_runtime_get_noresume() in coda_probe(), and one pm_runtime_put_sync() in coda_fw_callback(). By the time coda_remove() is called, balance is already restored. regards Philipp
> Hi Dinghao, > > thank you for the patch! The first part is fine, but I think the second > part is not necessary, see below: > > On Sat, May 23, 2020 at 06:03:32PM +0800, Dinghao Liu wrote: > > When coda_firmware_request() returns an error code, > > a pairing runtime PM usage counter decrement is needed > > to keep the counter balanced. > > > > Also, the caller expects coda_probe() to increase PM > > usage counter, there should be a refcount decrement > > in coda_remove() to keep the counter balanced. > > coda_probe() increments the usage counter only until coda_fw_callback() > decrements it again. Where is the imbalance? > You are right, I missed coda_firmware_request() before and thank you for your correction! I will fix this in the next edition of patch. Regards, Dinghao > > Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> > > --- > > drivers/media/platform/coda/coda-common.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/media/platform/coda/coda-common.c b/drivers/media/platform/coda/coda-common.c > > index d0d093dd8f7c..550e9a1266da 100644 > > --- a/drivers/media/platform/coda/coda-common.c > > +++ b/drivers/media/platform/coda/coda-common.c > > @@ -3119,6 +3119,8 @@ static int coda_probe(struct platform_device *pdev) > > return 0; > > > > err_alloc_workqueue: > > + pm_runtime_disable(&pdev->dev); > > + pm_runtime_put_noidle(&pdev->dev); > > These seem right, they balance out the pm_runtime_enable() > and pm_runtime_get_noresume() right before the error. > > > destroy_workqueue(dev->workqueue); > > err_v4l2_register: > > v4l2_device_unregister(&dev->v4l2_dev); > > @@ -3136,6 +3138,7 @@ static int coda_remove(struct platform_device *pdev) > > } > > if (dev->m2m_dev) > > v4l2_m2m_release(dev->m2m_dev); > > + pm_runtime_put_noidle(&pdev->dev); > > I think this is incorrect. There is one pm_runtime_get_noresume() in > coda_probe(), and one pm_runtime_put_sync() in coda_fw_callback(). > By the time coda_remove() is called, balance is already restored. > > regards > Philipp
diff --git a/drivers/media/platform/coda/coda-common.c b/drivers/media/platform/coda/coda-common.c index d0d093dd8f7c..550e9a1266da 100644 --- a/drivers/media/platform/coda/coda-common.c +++ b/drivers/media/platform/coda/coda-common.c @@ -3119,6 +3119,8 @@ static int coda_probe(struct platform_device *pdev) return 0; err_alloc_workqueue: + pm_runtime_disable(&pdev->dev); + pm_runtime_put_noidle(&pdev->dev); destroy_workqueue(dev->workqueue); err_v4l2_register: v4l2_device_unregister(&dev->v4l2_dev); @@ -3136,6 +3138,7 @@ static int coda_remove(struct platform_device *pdev) } if (dev->m2m_dev) v4l2_m2m_release(dev->m2m_dev); + pm_runtime_put_noidle(&pdev->dev); pm_runtime_disable(&pdev->dev); v4l2_device_unregister(&dev->v4l2_dev); destroy_workqueue(dev->workqueue);
When coda_firmware_request() returns an error code, a pairing runtime PM usage counter decrement is needed to keep the counter balanced. Also, the caller expects coda_probe() to increase PM usage counter, there should be a refcount decrement in coda_remove() to keep the counter balanced. Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> --- drivers/media/platform/coda/coda-common.c | 3 +++ 1 file changed, 3 insertions(+)