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* [PATCH] i2c: stm32f7: Fix runtime PM imbalance in stm32f7_i2c_reg_slave
@ 2020-05-21  7:05 Dinghao Liu
  2020-05-26  8:34 ` Alain Volmat
  0 siblings, 1 reply; 4+ messages in thread
From: Dinghao Liu @ 2020-05-21  7:05 UTC (permalink / raw)
  To: dinghao.liu, kjlu
  Cc: Pierre-Yves MORDRET, Maxime Coquelin, Alexandre Torgue,
	linux-i2c, linux-stm32, linux-arm-kernel, linux-kernel

pm_runtime_get_sync() increments the runtime PM usage counter even
the call 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@zju.edu.cn>
---
 drivers/i2c/busses/i2c-stm32f7.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index 330ffed011e0..602cf35649c8 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -1767,8 +1767,10 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
 		return ret;
 
 	ret = pm_runtime_get_sync(dev);
-	if (ret < 0)
+	if (ret < 0) {
+		pm_runtime_put_autosuspend(dev);
 		return ret;
+	}
 
 	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
 		stm32f7_i2c_enable_wakeup(i2c_dev, true);
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH] i2c: stm32f7: Fix runtime PM imbalance in stm32f7_i2c_reg_slave
  2020-05-21  7:05 [PATCH] i2c: stm32f7: Fix runtime PM imbalance in stm32f7_i2c_reg_slave Dinghao Liu
@ 2020-05-26  8:34 ` Alain Volmat
  2020-05-26 13:00   ` dinghao.liu
  0 siblings, 1 reply; 4+ messages in thread
From: Alain Volmat @ 2020-05-26  8:34 UTC (permalink / raw)
  To: Dinghao Liu
  Cc: kjlu, Pierre-Yves MORDRET, Maxime Coquelin, Alexandre Torgue,
	linux-i2c, linux-stm32, linux-arm-kernel, linux-kernel

Hi Dinghao,

Thanks for the patch. Indeed, this should be fixed.

Overall, there are several other calls to pm_runtime_get_sync within this
driver, would you like to fix them all at once ?

On Thu, May 21, 2020 at 03:05:07PM +0800, Dinghao Liu wrote:
> pm_runtime_get_sync() increments the runtime PM usage counter even
> the call 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@zju.edu.cn>
> ---
>  drivers/i2c/busses/i2c-stm32f7.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
> index 330ffed011e0..602cf35649c8 100644
> --- a/drivers/i2c/busses/i2c-stm32f7.c
> +++ b/drivers/i2c/busses/i2c-stm32f7.c
> @@ -1767,8 +1767,10 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
>  		return ret;
>  
>  	ret = pm_runtime_get_sync(dev);
> -	if (ret < 0)
> +	if (ret < 0) {
> +		pm_runtime_put_autosuspend(dev);

Considering that if we fail here there is a very good chance that this is due
to the resume failing, pm_runtime_put_noidle would probably make more sense
since pm_runtime_put_autosuspend will most probably fail as well.

>  		return ret;
> +	}
>  
>  	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
>  		stm32f7_i2c_enable_wakeup(i2c_dev, true);
> -- 
> 2.17.1
> 

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Re: [PATCH] i2c: stm32f7: Fix runtime PM imbalance in stm32f7_i2c_reg_slave
  2020-05-26  8:34 ` Alain Volmat
@ 2020-05-26 13:00   ` dinghao.liu
  2020-05-26 13:25     ` Alain Volmat
  0 siblings, 1 reply; 4+ messages in thread
From: dinghao.liu @ 2020-05-26 13:00 UTC (permalink / raw)
  To: Alain Volmat
  Cc: kjlu, Pierre-Yves MORDRET, Maxime Coquelin, Alexandre Torgue,
	linux-i2c, linux-stm32, linux-arm-kernel, linux-kernel


> Overall, there are several other calls to pm_runtime_get_sync within this
> driver, would you like to fix them all at once ?
> 

Sure, I will send a new patch to merge them all.

> On Thu, May 21, 2020 at 03:05:07PM +0800, Dinghao Liu wrote:
> > pm_runtime_get_sync() increments the runtime PM usage counter even
> > the call 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@zju.edu.cn>
> > ---
> >  drivers/i2c/busses/i2c-stm32f7.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
> > index 330ffed011e0..602cf35649c8 100644
> > --- a/drivers/i2c/busses/i2c-stm32f7.c
> > +++ b/drivers/i2c/busses/i2c-stm32f7.c
> > @@ -1767,8 +1767,10 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
> >  		return ret;
> >  
> >  	ret = pm_runtime_get_sync(dev);
> > -	if (ret < 0)
> > +	if (ret < 0) {
> > +		pm_runtime_put_autosuspend(dev);
> 
> Considering that if we fail here there is a very good chance that this is due
> to the resume failing, pm_runtime_put_noidle would probably make more sense
> since pm_runtime_put_autosuspend will most probably fail as well.
> 

Agree. Thank you for your advice!

Regards.
Dinghao

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Re: [PATCH] i2c: stm32f7: Fix runtime PM imbalance in stm32f7_i2c_reg_slave
  2020-05-26 13:00   ` dinghao.liu
@ 2020-05-26 13:25     ` Alain Volmat
  0 siblings, 0 replies; 4+ messages in thread
From: Alain Volmat @ 2020-05-26 13:25 UTC (permalink / raw)
  To: dinghao.liu
  Cc: kjlu, Pierre-Yves MORDRET, Maxime Coquelin, Alexandre Torgue,
	linux-i2c, linux-stm32, linux-arm-kernel, linux-kernel

On Tue, May 26, 2020 at 09:00:23PM +0800, dinghao.liu@zju.edu.cn wrote:
> 
> > Overall, there are several other calls to pm_runtime_get_sync within this
> > driver, would you like to fix them all at once ?
> > 
> 
> Sure, I will send a new patch to merge them all.

Thanks, you might want to add a Fixes: tag in your commit message as well.

> 
> > On Thu, May 21, 2020 at 03:05:07PM +0800, Dinghao Liu wrote:
> > > pm_runtime_get_sync() increments the runtime PM usage counter even
> > > the call 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@zju.edu.cn>
> > > ---
> > >  drivers/i2c/busses/i2c-stm32f7.c | 4 +++-
> > >  1 file changed, 3 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
> > > index 330ffed011e0..602cf35649c8 100644
> > > --- a/drivers/i2c/busses/i2c-stm32f7.c
> > > +++ b/drivers/i2c/busses/i2c-stm32f7.c
> > > @@ -1767,8 +1767,10 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
> > >  		return ret;
> > >  
> > >  	ret = pm_runtime_get_sync(dev);
> > > -	if (ret < 0)
> > > +	if (ret < 0) {
> > > +		pm_runtime_put_autosuspend(dev);
> > 
> > Considering that if we fail here there is a very good chance that this is due
> > to the resume failing, pm_runtime_put_noidle would probably make more sense
> > since pm_runtime_put_autosuspend will most probably fail as well.
> > 
> 
> Agree. Thank you for your advice!
> 
> Regards.
> Dinghao

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2020-05-26 13:26 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2020-05-21  7:05 [PATCH] i2c: stm32f7: Fix runtime PM imbalance in stm32f7_i2c_reg_slave Dinghao Liu
2020-05-26  8:34 ` Alain Volmat
2020-05-26 13:00   ` dinghao.liu
2020-05-26 13:25     ` Alain Volmat

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