Messages in this thread | | | Date | Sat, 11 Dec 2021 13:25:20 +0300 | Subject | Re: [PATCH v1 1/2] ata: libahci_platform: Get rid of dup message when IRQ can't be retrieved | From | Sergey Shtylyov <> |
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Hello!
On 11.12.2021 2:45, 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. > > Thinking more about this, shouldn't this change go into platform_get_irq() > instead of platform_get_irq_optional() ?
Why? platform_get_irq() currently just calls platform_get_irq_optional()...
> The way I see it, I think that the intended behavior for > platform_get_irq_optional() is: > 1) If have IRQ, return it, always > 0 > 2) If no IRQ, return 0
That does include the IRQ0 case, right?
> 3) If error, return < 0 > no ?
I completely agree, I (after thinking a bit) have no issues with that...
> And for platform_get_irq(), case (2) becomes an error. > Is this the intended semantic ?
I don't see how it's different from the current behavior. But we can do that as well, I just don't see whether it's really better...
> I am really not sure here as the functions kdoc description and the code do not > match. Which one is correct ?
It seems both are wrong. :-)
[...]
MBR, Sergey
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