devfreq: tegra: fix error code in tegra_devfreq_probe()

Submitted by Gustavo A. R. Silva on June 30, 2017, 7:22 a.m.

Details

Message ID 20170630072211.GA21867@embeddedgus
State New
Headers show

Commit Message

Gustavo A. R. Silva June 30, 2017, 7:22 a.m.
Print and propagate the return value of platform_get_irq on failure.

Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
---
 drivers/devfreq/tegra-devfreq.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Chanwoo Choi June 30, 2017, 8:02 a.m.
Hi,

On 2017년 06월 30일 16:22, Gustavo A. R. Silva wrote:
> Print and propagate the return value of platform_get_irq on failure.
> 
> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
> ---
>  drivers/devfreq/tegra-devfreq.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/devfreq/tegra-devfreq.c b/drivers/devfreq/tegra-devfreq.c
> index 214fff9..ae71215 100644
> --- a/drivers/devfreq/tegra-devfreq.c
> +++ b/drivers/devfreq/tegra-devfreq.c
> @@ -688,9 +688,9 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>  	}
>  
>  	irq = platform_get_irq(pdev, 0);
> -	if (irq <= 0) {
> -		dev_err(&pdev->dev, "Failed to get IRQ\n");
> -		return -ENODEV;
> +	if (irq < 0) {
> +		dev_err(&pdev->dev, "Failed to get IRQ: %d\n", irq);
> +		return irq;
>  	}
>  
>  	platform_set_drvdata(pdev, tegra);
> 

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
MyungJoo Ham July 1, 2017, 7:42 a.m.
On Fri, Jun 30, 2017 at 5:02 PM, Chanwoo Choi <cw00.choi@samsung.com> wrote:
> Hi,
>
> On 2017년 06월 30일 16:22, Gustavo A. R. Silva wrote:
>> Print and propagate the return value of platform_get_irq on failure.
>>
>> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
>> ---
>>  drivers/devfreq/tegra-devfreq.c | 6 +++---
>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/devfreq/tegra-devfreq.c b/drivers/devfreq/tegra-devfreq.c
>> index 214fff9..ae71215 100644
>> --- a/drivers/devfreq/tegra-devfreq.c
>> +++ b/drivers/devfreq/tegra-devfreq.c
>> @@ -688,9 +688,9 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>>       }
>>
>>       irq = platform_get_irq(pdev, 0);
>> -     if (irq <= 0) {
>> -             dev_err(&pdev->dev, "Failed to get IRQ\n");
>> -             return -ENODEV;
>> +     if (irq < 0) {
>> +             dev_err(&pdev->dev, "Failed to get IRQ: %d\n", irq);
>> +             return irq;
>>       }
>>
>>       platform_set_drvdata(pdev, tegra);
>>
>
> Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>

Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>

>
> --
> Best Regards,
> Chanwoo Choi
> Samsung Electronics
Jon Hunter July 3, 2017, 11:35 a.m.
On 30/06/17 08:22, Gustavo A. R. Silva wrote:
> Print and propagate the return value of platform_get_irq on failure.
> 
> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
> ---
>  drivers/devfreq/tegra-devfreq.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/devfreq/tegra-devfreq.c b/drivers/devfreq/tegra-devfreq.c
> index 214fff9..ae71215 100644
> --- a/drivers/devfreq/tegra-devfreq.c
> +++ b/drivers/devfreq/tegra-devfreq.c
> @@ -688,9 +688,9 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>  	}
>  
>  	irq = platform_get_irq(pdev, 0);
> -	if (irq <= 0) {
> -		dev_err(&pdev->dev, "Failed to get IRQ\n");
> -		return -ENODEV;
> +	if (irq < 0) {

The changelog does not describe the above change and if/why this is ok.
However, the original test looks fine to me and so I don't see a need to
change this.

> +		dev_err(&pdev->dev, "Failed to get IRQ: %d\n", irq);
> +		return irq;

Why not have ...

		return irq ? irq : -ENODEV;

Cheers
Jon
Gustavo A. R. Silva July 3, 2017, 11:59 a.m.
Hi Jon,

Quoting Jon Hunter <jonathanh@nvidia.com>:

> On 30/06/17 08:22, Gustavo A. R. Silva wrote:
>> Print and propagate the return value of platform_get_irq on failure.
>>
>> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
>> ---
>>  drivers/devfreq/tegra-devfreq.c | 6 +++---
>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/devfreq/tegra-devfreq.c  
>> b/drivers/devfreq/tegra-devfreq.c
>> index 214fff9..ae71215 100644
>> --- a/drivers/devfreq/tegra-devfreq.c
>> +++ b/drivers/devfreq/tegra-devfreq.c
>> @@ -688,9 +688,9 @@ static int tegra_devfreq_probe(struct  
>> platform_device *pdev)
>>  	}
>>
>>  	irq = platform_get_irq(pdev, 0);
>> -	if (irq <= 0) {
>> -		dev_err(&pdev->dev, "Failed to get IRQ\n");
>> -		return -ENODEV;
>> +	if (irq < 0) {
>
> The changelog does not describe the above change and if/why this is ok.
> However, the original test looks fine to me and so I don't see a need to
> change this.
>

You are right about the changelog. I think this one is much better:

platform_get_irq() returns an error code, but the tegra-devfreq
driver ignores it and always returns -ENODEV. This is not correct,
and prevents -EPROBE_DEFER from being propagated properly.

Notice that platform_get_irq() no longer returns 0 on error:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e330b9a6bb35dc7097a4f02cb1ae7b6f96df92af

Print error message and propagate the return value of
platform_get_irq on failure.


What do you think?

Thank you!
--
Gustavo A. R. Silva






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Jon Hunter July 3, 2017, 12:22 p.m.
On 03/07/17 12:59, Gustavo A. R. Silva wrote:
> Hi Jon,
> 
> Quoting Jon Hunter <jonathanh@nvidia.com>:
> 
>> On 30/06/17 08:22, Gustavo A. R. Silva wrote:
>>> Print and propagate the return value of platform_get_irq on failure.
>>>
>>> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
>>> ---
>>>  drivers/devfreq/tegra-devfreq.c | 6 +++---
>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/devfreq/tegra-devfreq.c
>>> b/drivers/devfreq/tegra-devfreq.c
>>> index 214fff9..ae71215 100644
>>> --- a/drivers/devfreq/tegra-devfreq.c
>>> +++ b/drivers/devfreq/tegra-devfreq.c
>>> @@ -688,9 +688,9 @@ static int tegra_devfreq_probe(struct
>>> platform_device *pdev)
>>>      }
>>>
>>>      irq = platform_get_irq(pdev, 0);
>>> -    if (irq <= 0) {
>>> -        dev_err(&pdev->dev, "Failed to get IRQ\n");
>>> -        return -ENODEV;
>>> +    if (irq < 0) {
>>
>> The changelog does not describe the above change and if/why this is ok.
>> However, the original test looks fine to me and so I don't see a need to
>> change this.
>>
> 
> You are right about the changelog. I think this one is much better:
> 
> platform_get_irq() returns an error code, but the tegra-devfreq
> driver ignores it and always returns -ENODEV. This is not correct,
> and prevents -EPROBE_DEFER from being propagated properly.
> 
> Notice that platform_get_irq() no longer returns 0 on error:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e330b9a6bb35dc7097a4f02cb1ae7b6f96df92af

Yes the above should be added to the changelog.

Looks like someone should update the following for consistency too ...

141 int platform_irq_count(struct platform_device *dev)
142 {
143         int ret, nr = 0;
144
145         while ((ret = platform_get_irq(dev, nr)) >= 0)
146                 nr++;

> 
> Print error message and propagate the return value of
> platform_get_irq on failure.
> 
> What do you think?
Fine with me.

Thanks!
Jon

Patch hide | download patch | download mbox

diff --git a/drivers/devfreq/tegra-devfreq.c b/drivers/devfreq/tegra-devfreq.c
index 214fff9..ae71215 100644
--- a/drivers/devfreq/tegra-devfreq.c
+++ b/drivers/devfreq/tegra-devfreq.c
@@ -688,9 +688,9 @@  static int tegra_devfreq_probe(struct platform_device *pdev)
 	}
 
 	irq = platform_get_irq(pdev, 0);
-	if (irq <= 0) {
-		dev_err(&pdev->dev, "Failed to get IRQ\n");
-		return -ENODEV;
+	if (irq < 0) {
+		dev_err(&pdev->dev, "Failed to get IRQ: %d\n", irq);
+		return irq;
 	}
 
 	platform_set_drvdata(pdev, tegra);