Re: [PATCH v1 1/2] ata: libahci_platform: Get rid of dup message when IRQ can't be retrieved

Sergey Shtylyov
2021-12-10T08:59:09Z

On 12/10/21 1:49 AM, Damien Le Moal wrote:

>> platform_get_irq() will print a message when it fails.
>> No need to repeat this.
>>
>> While at it, drop redundant check for 0 as platform_get_irq() spills
>> out a big WARN() in such case.
>
> The reason you should be able to remove the "if (!irq)" test is that
> platform_get_irq() never returns 0. At least, that is what the function kdoc
> says. But looking at platform_get_irq_optional(), which is called by
> platform_get_irq(), the out label is:
>
> WARN(ret == 0, "0 is an invalid IRQ number\n");
> return ret;
>
> So 0 will be returned as-is. That is rather weird. That should be fixed to
> return -ENXIO:
>
> if (WARN(ret == 0, "0 is an invalid IRQ number\n"))
> return -ENXIO;
> return ret;

My unmerged patch (https://marc.info/?l=linux-kernel&m=163623041902285) does this
but returns -EINVAL instead.

> Otherwise, I do not think that removing the "if (!irq)" hunk is safe. no ?

Of course it isn't...

>> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[...]

MBR, Sergey