2021-04-08 07:13:40

by Dinghao Liu

Subject: [PATCH] dmaengine: tegra20: Fix runtime PM imbalance in tegra_dma_issue_pending

pm_runtime_get_sync() will increase the rumtime PM counter
even it returns an error. Thus a pairing decrement is needed
to prevent refcount leak. Fix this by replacing this API with
pm_runtime_resume_and_get(), which will not change the runtime
PM counter on error.

Signed-off-by: Dinghao Liu <[email protected]>
---
drivers/dma/tegra20-apb-dma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
index 71827d9b0aa1..73178afaf4c2 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -723,7 +723,7 @@ static void tegra_dma_issue_pending(struct dma_chan *dc)
goto end;
}
if (!tdc->busy) {
- err = pm_runtime_get_sync(tdc->tdma->dev);
+ err = pm_runtime_resume_and_get(tdc->tdma->dev);
if (err < 0) {
dev_err(tdc2dev(tdc), "Failed to enable DMA\n");
goto end;
--
2.17.1

2021-04-08 12:34:07

by Jon Hunter

Subject: Re: [PATCH] dmaengine: tegra20: Fix runtime PM imbalance in tegra_dma_issue_pending

On 08/04/2021 08:11, Dinghao Liu wrote:
> pm_runtime_get_sync() will increase the rumtime PM counter
> even it returns an error. Thus a pairing decrement is needed
> to prevent refcount leak. Fix this by replacing this API with
> pm_runtime_resume_and_get(), which will not change the runtime
> PM counter on error.
>
> Signed-off-by: Dinghao Liu <[email protected]>
> ---
> drivers/dma/tegra20-apb-dma.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
> index 71827d9b0aa1..73178afaf4c2 100644
> --- a/drivers/dma/tegra20-apb-dma.c
> +++ b/drivers/dma/tegra20-apb-dma.c
> @@ -723,7 +723,7 @@ static void tegra_dma_issue_pending(struct dma_chan *dc)
> goto end;
> }
> if (!tdc->busy) {
> - err = pm_runtime_get_sync(tdc->tdma->dev);
> + err = pm_runtime_resume_and_get(tdc->tdma->dev);
> if (err < 0) {
> dev_err(tdc2dev(tdc), "Failed to enable DMA\n");
> goto end;
>


Thanks! Looks like there are two instances of this that need fixing.

Cheers
Jon

--
nvpublic

2021-04-09 08:28:22

by Dinghao Liu

Subject: Re: Re: [PATCH] dmaengine: tegra20: Fix runtime PM imbalance in tegra_dma_issue_pending

> On 08/04/2021 08:11, Dinghao Liu wrote:
> > pm_runtime_get_sync() will increase the rumtime PM counter
> > even it returns an error. Thus a pairing decrement is needed
> > to prevent refcount leak. Fix this by replacing this API with
> > pm_runtime_resume_and_get(), which will not change the runtime
> > PM counter on error.
> >
> > Signed-off-by: Dinghao Liu <[email protected]>
> > ---
> > drivers/dma/tegra20-apb-dma.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
> > index 71827d9b0aa1..73178afaf4c2 100644
> > --- a/drivers/dma/tegra20-apb-dma.c
> > +++ b/drivers/dma/tegra20-apb-dma.c
> > @@ -723,7 +723,7 @@ static void tegra_dma_issue_pending(struct dma_chan *dc)
> > goto end;
> > }
> > if (!tdc->busy) {
> > - err = pm_runtime_get_sync(tdc->tdma->dev);
> > + err = pm_runtime_resume_and_get(tdc->tdma->dev);
> > if (err < 0) {
> > dev_err(tdc2dev(tdc), "Failed to enable DMA\n");
> > goto end;
> >
>
>
> Thanks! Looks like there are two instances of this that need fixing.
>

Thanks for pointing out this! I will fix this and send a new patch soon.

Regards,
Dinghao