On 2021/12/10 17:59, Sergey Shtylyov wrote: > 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. Thinking more about this, shouldn't this change go into platform_get_irq() instead of 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 3) If error, return < 0 no ? And for platform_get_irq(), case (2) becomes an error. Is this the intended semantic ? I am really not sure here as the functions kdoc description and the code do not match. Which one is correct ? > >> 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@xxxxxxxxxxxxxxx> > [...] > > MBR, Sergey -- Damien Le Moal Western Digital Research
