Re: [PATCH] drivers/iio/adc/at91_adc.c: use devm_ functions

From: Lars-Peter Clausen
Date: Wed Aug 15 2012 - 05:02:17 EST


On 08/14/2012 10:32 PM, Jonathan Cameron wrote:
> Lars-Peter,
>
> Are you happy with this updated version? Can't immediately find any response
> from you to it.
>

I think it is ok, you can add my
Reviewed-by: Lars-Peter Clausen <lars@xxxxxxxxxx>.

One minor nitpick though.

> Jonathan
>> From: Julia Lawall <Julia.Lawall@xxxxxxx>
>>
>> The various devm_ functions allocate memory that is released when a driver
>> detaches. This patch uses these functions for data that is allocated in
>> the probe function of a platform device and is only freed in the remove
>> function.
>>
>> The call to platform_get_resource(pdev, IORESOURCE_MEM, 0) is moved coser
>> to the call to devm_request_and_ioremap, which is th first use of the
>> result of platform_get_resource.
>>
>> This does not use devm_request_irq to ensure that free_irq is executed
>> before its idev argument is freed.
>>
>> Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx>
>>
>> ---
>> drivers/iio/adc/at91_adc.c | 41 ++++++++---------------------------------
>> 1 file changed, 8 insertions(+), 33 deletions(-)
>>
>> diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
>> index f61780a..3506e3d 100644
>> --- a/drivers/iio/adc/at91_adc.c
>> +++ b/drivers/iio/adc/at91_adc.c
>> @@ -545,13 +545,6 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
>> goto error_free_device;
>> }
>>
>> - res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> - if (!res) {
>> - dev_err(&pdev->dev, "No resource defined\n");
>> - ret = -ENXIO;
>> - goto error_ret;
>> - }
>> -
>> platform_set_drvdata(pdev, idev);
>>
>> idev->dev.parent = &pdev->dev;
>> @@ -566,18 +559,13 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
>> goto error_free_device;
>> }
>>
>> - if (!request_mem_region(res->start, resource_size(res),
>> - "AT91 adc registers")) {
>> - dev_err(&pdev->dev, "Resources are unavailable.\n");
>> - ret = -EBUSY;
>> - goto error_free_device;
>> - }
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>
>> - st->reg_base = ioremap(res->start, resource_size(res));
>> + st->reg_base = devm_request_and_ioremap(&pdev->dev, res);
>> if (!st->reg_base) {
>> dev_err(&pdev->dev, "Failed to map registers.\n");

devm_request_and_ioremap will already print a error messages on it's own if
something goes wrong. So strictly speaking this one is redundant, but I don't
think it is necessary to do a resend just for this, maybe you can remove the
extra dev_err when you apply the patch.
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