2020-05-22 04:14:42

by Tiezhu Yang

Subject: [PATCH 2/3] gpio: pxa: Fix return value of pxa_gpio_probe()

When call function devm_platform_ioremap_resource(), we should use IS_ERR()
to check the return value and return PTR_ERR() if failed.

Fixes: 542c25b7a209 ("drivers: gpio: pxa: use devm_platform_ioremap_resource()")
Signed-off-by: Tiezhu Yang <[email protected]>
---
drivers/gpio/gpio-pxa.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-pxa.c b/drivers/gpio/gpio-pxa.c
index 1361270..0cb6600 100644
--- a/drivers/gpio/gpio-pxa.c
+++ b/drivers/gpio/gpio-pxa.c
@@ -660,8 +660,8 @@ static int pxa_gpio_probe(struct platform_device *pdev)
pchip->irq1 = irq1;

gpio_reg_base = devm_platform_ioremap_resource(pdev, 0);
- if (!gpio_reg_base)
- return -EINVAL;
+ if (IS_ERR(gpio_reg_base))
+ return PTR_ERR(gpio_reg_base);

clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(clk)) {
--
2.1.0

2020-05-22 19:10:10

by Robert Jarzmik

Subject: Re: [PATCH 2/3] gpio: pxa: Fix return value of pxa_gpio_probe()

Tiezhu Yang <[email protected]> writes:

> When call function devm_platform_ioremap_resource(), we should use IS_ERR()
> to check the return value and return PTR_ERR() if failed.
>
> Fixes: 542c25b7a209 ("drivers: gpio: pxa: use devm_platform_ioremap_resource()")
> Signed-off-by: Tiezhu Yang <[email protected]>
> ---
> drivers/gpio/gpio-pxa.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpio/gpio-pxa.c b/drivers/gpio/gpio-pxa.c
> index 1361270..0cb6600 100644
> --- a/drivers/gpio/gpio-pxa.c
> +++ b/drivers/gpio/gpio-pxa.c
> @@ -660,8 +660,8 @@ static int pxa_gpio_probe(struct platform_device *pdev)
> pchip->irq1 = irq1;
>
> gpio_reg_base = devm_platform_ioremap_resource(pdev, 0);
> - if (!gpio_reg_base)
> - return -EINVAL;
> + if (IS_ERR(gpio_reg_base))
> + return PTR_ERR(gpio_reg_base);
As far as I know, devm_platform_ioremap_resource() could return NULL which is
not handled by this test (unless __devm_ioremap() semantics changed since I had
a look).

Therefore, this patch is incorrect, or rather incomplete.

Cheers.

--
Robert

2020-05-23 03:27:46

by Tiezhu Yang

Subject: Re: [PATCH 2/3] gpio: pxa: Fix return value of pxa_gpio_probe()

On 05/23/2020 03:07 AM, Robert Jarzmik wrote:
> Tiezhu Yang <[email protected]> writes:
>
>> When call function devm_platform_ioremap_resource(), we should use IS_ERR()
>> to check the return value and return PTR_ERR() if failed.
>>
>> Fixes: 542c25b7a209 ("drivers: gpio: pxa: use devm_platform_ioremap_resource()")
>> Signed-off-by: Tiezhu Yang <[email protected]>
>> ---
>> drivers/gpio/gpio-pxa.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpio/gpio-pxa.c b/drivers/gpio/gpio-pxa.c
>> index 1361270..0cb6600 100644
>> --- a/drivers/gpio/gpio-pxa.c
>> +++ b/drivers/gpio/gpio-pxa.c
>> @@ -660,8 +660,8 @@ static int pxa_gpio_probe(struct platform_device *pdev)
>> pchip->irq1 = irq1;
>>
>> gpio_reg_base = devm_platform_ioremap_resource(pdev, 0);
>> - if (!gpio_reg_base)
>> - return -EINVAL;
>> + if (IS_ERR(gpio_reg_base))
>> + return PTR_ERR(gpio_reg_base);
> As far as I know, devm_platform_ioremap_resource() could return NULL which is
> not handled by this test (unless __devm_ioremap() semantics changed since I had
> a look).

Hi Robert,

In the function __devm_ioremap_resource(), if __devm_ioremap returns NULL,
it will return IOMEM_ERR_PTR(-ENOMEM).

devm_platform_ioremap_resource()
devm_ioremap_resource()
__devm_ioremap_resource()
__devm_ioremap()

static void __iomem *
__devm_ioremap_resource(struct device *dev, const struct resource *res,
enum devm_ioremap_type type)
{
...
dest_ptr = __devm_ioremap(dev, res->start, size, type);
if (!dest_ptr) {
dev_err(dev, "ioremap failed for resource %pR\n", res);
devm_release_mem_region(dev, res->start, size);
dest_ptr = IOMEM_ERR_PTR(-ENOMEM);
}

return dest_ptr;
}

And also, we can see the comment of devm_ioremap_resource():

Usage example:

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(base))
return PTR_ERR(base);

>
> Therefore, this patch is incorrect, or rather incomplete.

So I think this patch is correct, do I miss something?

Thanks,
Tiezhu Yang

>
> Cheers.
>

2020-05-25 17:27:53

by Bartosz Golaszewski

Subject: Re: [PATCH 2/3] gpio: pxa: Fix return value of pxa_gpio_probe()

sob., 23 maj 2020 o 05:25 Tiezhu Yang <[email protected]> napisał(a):
>
> On 05/23/2020 03:07 AM, Robert Jarzmik wrote:
> > Tiezhu Yang <[email protected]> writes:
> >
> >> When call function devm_platform_ioremap_resource(), we should use IS_ERR()
> >> to check the return value and return PTR_ERR() if failed.
> >>
> >> Fixes: 542c25b7a209 ("drivers: gpio: pxa: use devm_platform_ioremap_resource()")
> >> Signed-off-by: Tiezhu Yang <[email protected]>
> >> ---
> >> drivers/gpio/gpio-pxa.c | 4 ++--
> >> 1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/gpio/gpio-pxa.c b/drivers/gpio/gpio-pxa.c
> >> index 1361270..0cb6600 100644
> >> --- a/drivers/gpio/gpio-pxa.c
> >> +++ b/drivers/gpio/gpio-pxa.c
> >> @@ -660,8 +660,8 @@ static int pxa_gpio_probe(struct platform_device *pdev)
> >> pchip->irq1 = irq1;
> >>
> >> gpio_reg_base = devm_platform_ioremap_resource(pdev, 0);
> >> - if (!gpio_reg_base)
> >> - return -EINVAL;
> >> + if (IS_ERR(gpio_reg_base))
> >> + return PTR_ERR(gpio_reg_base);
> > As far as I know, devm_platform_ioremap_resource() could return NULL which is
> > not handled by this test (unless __devm_ioremap() semantics changed since I had
> > a look).
>
> Hi Robert,
>
> In the function __devm_ioremap_resource(), if __devm_ioremap returns NULL,
> it will return IOMEM_ERR_PTR(-ENOMEM).
>
> devm_platform_ioremap_resource()
> devm_ioremap_resource()
> __devm_ioremap_resource()
> __devm_ioremap()
>
> static void __iomem *
> __devm_ioremap_resource(struct device *dev, const struct resource *res,
> enum devm_ioremap_type type)
> {
> ...
> dest_ptr = __devm_ioremap(dev, res->start, size, type);
> if (!dest_ptr) {
> dev_err(dev, "ioremap failed for resource %pR\n", res);
> devm_release_mem_region(dev, res->start, size);
> dest_ptr = IOMEM_ERR_PTR(-ENOMEM);
> }
>
> return dest_ptr;
> }
>
> And also, we can see the comment of devm_ioremap_resource():
>
> Usage example:
>
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> base = devm_ioremap_resource(&pdev->dev, res);
> if (IS_ERR(base))
> return PTR_ERR(base);
>
> >
> > Therefore, this patch is incorrect, or rather incomplete.
>
> So I think this patch is correct, do I miss something?
>
>

Yes, this patch is correct. Applied for fixes.

Bart

2020-05-27 19:23:38

by Robert Jarzmik

Subject: Re: [PATCH 2/3] gpio: pxa: Fix return value of pxa_gpio_probe()

Tiezhu Yang <[email protected]> writes:

> On 05/23/2020 03:07 AM, Robert Jarzmik wrote:
>> Tiezhu Yang <[email protected]> writes:
>>
>>> When call function devm_platform_ioremap_resource(), we should use IS_ERR()
>>> to check the return value and return PTR_ERR() if failed.
>>>
>>> Fixes: 542c25b7a209 ("drivers: gpio: pxa: use devm_platform_ioremap_resource()")
>>> Signed-off-by: Tiezhu Yang <[email protected]>
>>> ---
>>> drivers/gpio/gpio-pxa.c | 4 ++--
>>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpio/gpio-pxa.c b/drivers/gpio/gpio-pxa.c
>>> index 1361270..0cb6600 100644
>>> --- a/drivers/gpio/gpio-pxa.c
>>> +++ b/drivers/gpio/gpio-pxa.c
>>> @@ -660,8 +660,8 @@ static int pxa_gpio_probe(struct platform_device *pdev)
>>> pchip->irq1 = irq1;
>>> gpio_reg_base = devm_platform_ioremap_resource(pdev, 0);
>>> - if (!gpio_reg_base)
>>> - return -EINVAL;
>>> + if (IS_ERR(gpio_reg_base))
>>> + return PTR_ERR(gpio_reg_base);
>> As far as I know, devm_platform_ioremap_resource() could return NULL which is
>> not handled by this test (unless __devm_ioremap() semantics changed since I had
>> a look).
>
> Hi Robert,
>
> In the function __devm_ioremap_resource(), if __devm_ioremap returns NULL,
> it will return IOMEM_ERR_PTR(-ENOMEM).
>
> devm_platform_ioremap_resource()
> devm_ioremap_resource()
> __devm_ioremap_resource()
> __devm_ioremap()
>
> static void __iomem *
> __devm_ioremap_resource(struct device *dev, const struct resource *res,
> enum devm_ioremap_type type)
> {
> ...
> dest_ptr = __devm_ioremap(dev, res->start, size, type);
> if (!dest_ptr) {
> dev_err(dev, "ioremap failed for resource %pR\n", res);
> devm_release_mem_region(dev, res->start, size);
> dest_ptr = IOMEM_ERR_PTR(-ENOMEM);
> }
>
> return dest_ptr;
> }
>
> And also, we can see the comment of devm_ioremap_resource():
>
> Usage example:
>
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> base = devm_ioremap_resource(&pdev->dev, res);
> if (IS_ERR(base))
> return PTR_ERR(base);
>
>>
>> Therefore, this patch is incorrect, or rather incomplete.
>
> So I think this patch is correct, do I miss something?
You're right, my bad, didn't see the test in __devm_ioremap_resource().

Cheers.

--
Robert