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

Damien Le Moal
2021-12-09T22:49:44Z

On 2021/12/09 23:59, Andy Shevchenko 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;

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

>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> drivers/ata/libahci_platform.c | 7 +------
> 1 file changed, 1 insertion(+), 6 deletions(-)
>
> diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
> index 0910441321f7..1af642c84e7b 100644
> --- a/drivers/ata/libahci_platform.c
> +++ b/drivers/ata/libahci_platform.c
> @@ -579,13 +579,8 @@ int ahci_platform_init_host(struct platform_device *pdev,
> int i, irq, n_ports, rc;
>
> irq = platform_get_irq(pdev, 0);
> - if (irq < 0) {
> - if (irq != -EPROBE_DEFER)
> - dev_err(dev, "no irq\n");
> + if (irq < 0)
> return irq;
> - }
> - if (!irq)
> - return -EINVAL;
>
> hpriv->irq = irq;
>

--
Damien Le Moal
Western Digital Research