diff mbox

[1/5,v4] ASoC: ep93xx-ac97: Fix platform_get_irq's error checking

Message ID 082d4479211d425219f4ab275ecc12e1011eca2f.1511062844.git.arvind.yadav.cs@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Arvind Yadav Nov. 19, 2017, 4:15 a.m. UTC
The platform_get_irq() function returns negative if an error occurs.
zero or positive number on success. platform_get_irq() error checking
for zero is not correct.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
---
changes in v2 :
               irq was unsigned. so changed it to signed.
changes in v3 :
              Add failure case '<= 0' instead of '< 0'. IRQ0 is not valid.
changes in v4 :
              Return -ENODEV insted of irq.

 sound/soc/cirrus/ep93xx-ac97.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Alexandre Belloni Nov. 20, 2017, 1:37 p.m. UTC | #1
On 19/11/2017 at 09:45:00 +0530, Arvind Yadav wrote:
> The platform_get_irq() function returns negative if an error occurs.
> zero or positive number on success. platform_get_irq() error checking
> for zero is not correct.
> 
> Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
> ---
> changes in v2 :
>                irq was unsigned. so changed it to signed.
> changes in v3 :
>               Add failure case '<= 0' instead of '< 0'. IRQ0 is not valid.
> changes in v4 :
>               Return -ENODEV insted of irq.
> 

To ensure this doesn't get applied: platform_get_irq can return
-EPROBE_DEFER and this must be handled properly.

(Or maybe this has never caused anything and never failed at all and
nobody cares).


>  sound/soc/cirrus/ep93xx-ac97.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/sound/soc/cirrus/ep93xx-ac97.c b/sound/soc/cirrus/ep93xx-ac97.c
> index bbf7a92..efeecee 100644
> --- a/sound/soc/cirrus/ep93xx-ac97.c
> +++ b/sound/soc/cirrus/ep93xx-ac97.c
> @@ -365,7 +365,7 @@ static int ep93xx_ac97_probe(struct platform_device *pdev)
>  {
>  	struct ep93xx_ac97_info *info;
>  	struct resource *res;
> -	unsigned int irq;
> +	int irq;
>  	int ret;
>  
>  	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
> @@ -378,7 +378,7 @@ static int ep93xx_ac97_probe(struct platform_device *pdev)
>  		return PTR_ERR(info->regs);
>  
>  	irq = platform_get_irq(pdev, 0);
> -	if (!irq)
> +	if (irq <= 0)
>  		return -ENODEV;
>  
>  	ret = devm_request_irq(&pdev->dev, irq, ep93xx_ac97_interrupt,
> -- 
> 2.7.4
> 
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@alsa-project.org
> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
Arvind Yadav Nov. 20, 2017, 4:01 p.m. UTC | #2
Hi,

On Monday 20 November 2017 07:07 PM, Alexandre Belloni wrote:
> On 19/11/2017 at 09:45:00 +0530, Arvind Yadav wrote:
>> The platform_get_irq() function returns negative if an error occurs.
>> zero or positive number on success. platform_get_irq() error checking
>> for zero is not correct.
>>
>> Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
>> ---
>> changes in v2 :
>>                 irq was unsigned. so changed it to signed.
>> changes in v3 :
>>                Add failure case '<= 0' instead of '< 0'. IRQ0 is not valid.
>> changes in v4 :
>>                Return -ENODEV insted of irq.
>>
> To ensure this doesn't get applied: platform_get_irq can return
> -EPROBE_DEFER and this must be handled properly.
>
> (Or maybe this has never caused anything and never failed at all and
> nobody cares).
Yes, you are right. We should retry to get an irq for device. But ASoC
  driver is not retrying. if platfore_get_irq() fail here, Driver is 
throwing an error.
and this patch is only to fix error checking which is not correct in 
Driver.

~arvind

>
>>   sound/soc/cirrus/ep93xx-ac97.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/sound/soc/cirrus/ep93xx-ac97.c b/sound/soc/cirrus/ep93xx-ac97.c
>> index bbf7a92..efeecee 100644
>> --- a/sound/soc/cirrus/ep93xx-ac97.c
>> +++ b/sound/soc/cirrus/ep93xx-ac97.c
>> @@ -365,7 +365,7 @@ static int ep93xx_ac97_probe(struct platform_device *pdev)
>>   {
>>   	struct ep93xx_ac97_info *info;
>>   	struct resource *res;
>> -	unsigned int irq;
>> +	int irq;
>>   	int ret;
>>   
>>   	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
>> @@ -378,7 +378,7 @@ static int ep93xx_ac97_probe(struct platform_device *pdev)
>>   		return PTR_ERR(info->regs);
>>   
>>   	irq = platform_get_irq(pdev, 0);
>> -	if (!irq)
>> +	if (irq <= 0)
>>   		return -ENODEV;
>>   
>>   	ret = devm_request_irq(&pdev->dev, irq, ep93xx_ac97_interrupt,
>> -- 
>> 2.7.4
>>
>> _______________________________________________
>> Alsa-devel mailing list
>> Alsa-devel@alsa-project.org
>> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
Mark Brown Nov. 29, 2017, 10:53 a.m. UTC | #3
On Mon, Nov 20, 2017 at 09:31:40PM +0530, arvindY wrote:
> On Monday 20 November 2017 07:07 PM, Alexandre Belloni wrote:
> > On 19/11/2017 at 09:45:00 +0530, Arvind Yadav wrote:

> > To ensure this doesn't get applied: platform_get_irq can return
> > -EPROBE_DEFER and this must be handled properly.

> Yes, you are right. We should retry to get an irq for device. But ASoC
>  driver is not retrying. if platfore_get_irq() fail here, Driver is throwing
> an error.
> and this patch is only to fix error checking which is not correct in Driver.

> > >   	irq = platform_get_irq(pdev, 0);
> > > -	if (!irq)
> > > +	if (irq <= 0)
> > >   		return -ENODEV;

This is just squashing all error codes into -ENODEV, we'd be handling
probe deferral properly if we just returned the raw error code here.  We
need separate handling for irq == 0 which is an error but not an error
code and for cases where we've got an error code.
diff mbox

Patch

diff --git a/sound/soc/cirrus/ep93xx-ac97.c b/sound/soc/cirrus/ep93xx-ac97.c
index bbf7a92..efeecee 100644
--- a/sound/soc/cirrus/ep93xx-ac97.c
+++ b/sound/soc/cirrus/ep93xx-ac97.c
@@ -365,7 +365,7 @@  static int ep93xx_ac97_probe(struct platform_device *pdev)
 {
 	struct ep93xx_ac97_info *info;
 	struct resource *res;
-	unsigned int irq;
+	int irq;
 	int ret;
 
 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
@@ -378,7 +378,7 @@  static int ep93xx_ac97_probe(struct platform_device *pdev)
 		return PTR_ERR(info->regs);
 
 	irq = platform_get_irq(pdev, 0);
-	if (!irq)
+	if (irq <= 0)
 		return -ENODEV;
 
 	ret = devm_request_irq(&pdev->dev, irq, ep93xx_ac97_interrupt,