[PATCH] [v3] dmaengine: tegra210-adma: Fix runtime PM imbalance on error

[PATCH] [v3] dmaengine: tegra210-adma: Fix runtime PM imbalance on error

[Dinghao Liu]

pm_runtime_get_sync() increments the runtime PM usage counter even
when it returns an error code. Thus a pairing decrement is needed on
the error handling path to keep the counter balanced.

Signed-off-by: Dinghao Liu <dinghao.liu-Y5EWUtBUdg4nDS1+zs4M5A@public.gmane.org>
---

Changelog:

v2: - Merge two patches that fix runtime PM imbalance in
      tegra_adma_probe() and tegra_adma_alloc_chan_resources()
      respectively.

v3: - Use pm_runtime_put_noidle() instead of pm_runtime_put_sync()
      in tegra_adma_alloc_chan_resources().
---
 drivers/dma/tegra210-adma.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/tegra210-adma.c b/drivers/dma/tegra210-adma.c
index db58d7e4f9fe..bfa8800dfb4c 100644
--- a/drivers/dma/tegra210-adma.c
+++ b/drivers/dma/tegra210-adma.c
@@ -658,6 +658,7 @@ static int tegra_adma_alloc_chan_resources(struct dma_chan *dc)
 
 	ret = pm_runtime_get_sync(tdc2dev(tdc));
 	if (ret < 0) {
+		pm_runtime_put_noidle(tdc2dev(tdc));
 		free_irq(tdc->irq, tdc);
 		return ret;
 	}
@@ -870,7 +871,7 @@ static int tegra_adma_probe(struct platform_device *pdev)
 
 	ret = pm_runtime_get_sync(&pdev->dev);
 	if (ret < 0)
-		goto rpm_disable;
+		goto rpm_put;
 
 	ret = tegra_adma_init(tdma);
 	if (ret)
@@ -921,7 +922,6 @@ static int tegra_adma_probe(struct platform_device *pdev)
 	dma_async_device_unregister(&tdma->dma_dev);
 rpm_put:
 	pm_runtime_put_sync(&pdev->dev);
-rpm_disable:
 	pm_runtime_disable(&pdev->dev);
 irq_dispose:
 	while (--i >= 0)
-- 
2.17.1

Re: [PATCH] [v3] dmaengine: tegra210-adma: Fix runtime PM imbalance on error

[Jon Hunter]

On 18/06/2020 11:57, Dinghao Liu wrote:
> pm_runtime_get_sync() increments the runtime PM usage counter even
> when it returns an error code. Thus a pairing decrement is needed on
> the error handling path to keep the counter balanced.
> 
> Signed-off-by: Dinghao Liu <dinghao.liu-Y5EWUtBUdg4nDS1+zs4M5A@public.gmane.org>
> ---
> 
> Changelog:
> 
> v2: - Merge two patches that fix runtime PM imbalance in
>       tegra_adma_probe() and tegra_adma_alloc_chan_resources()
>       respectively.
> 
> v3: - Use pm_runtime_put_noidle() instead of pm_runtime_put_sync()
>       in tegra_adma_alloc_chan_resources().
> ---
>  drivers/dma/tegra210-adma.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/dma/tegra210-adma.c b/drivers/dma/tegra210-adma.c
> index db58d7e4f9fe..bfa8800dfb4c 100644
> --- a/drivers/dma/tegra210-adma.c
> +++ b/drivers/dma/tegra210-adma.c
> @@ -658,6 +658,7 @@ static int tegra_adma_alloc_chan_resources(struct dma_chan *dc)
>  
>  	ret = pm_runtime_get_sync(tdc2dev(tdc));
>  	if (ret < 0) {
> +		pm_runtime_put_noidle(tdc2dev(tdc));

Why noidle?

Jon

-- 
nvpublic

Re: Re: [PATCH] [v3] dmaengine: tegra210-adma: Fix runtime PM imbalance on error

[dinghao.liu-Y5EWUtBUdg4nDS1+zs4M5A]

> 
> Why noidle?
> 

_noidle is enough for fixing this bug. _sync may suspend
the device beyond expectation.

Regards,
Dinghao

Re: [PATCH] [v3] dmaengine: tegra210-adma: Fix runtime PM imbalance on error

[Jon Hunter]

On 19/06/2020 02:59, dinghao.liu-Y5EWUtBUdg4nDS1+zs4M5A@public.gmane.org wrote:
>>
>> Why noidle?
>>
> 
> _noidle is enough for fixing this bug. _sync may suspend
> the device beyond expectation.

In that case, then the other instance you are fixing with this patch is
not correct.

Jon

-- 
nvpublic

Re: Re: [PATCH] [v3] dmaengine: tegra210-adma: Fix runtime PM imbalance on error

[dinghao.liu-Y5EWUtBUdg4nDS1+zs4M5A]

> >>
> >> Why noidle?
> >>
> > 
> > _noidle is enough for fixing this bug. _sync may suspend
> > the device beyond expectation.
> 
> In that case, then the other instance you are fixing with this patch is
> not correct.
> 

Fine. I will fix this soon.

Regards,
Dinghao