On Sat, Dec 11, 2021 at 08:45:51AM +0900, Damien Le Moal wrote: > 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 ? At least this is my understanding on how it _should_ be. > And for platform_get_irq(), case (2) becomes an error. Precisely! > 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 ? The problem is that platform_get_irq_optional() doesn't follow above mentioned logic and needs to be fixed. While trying to fix that it appears that it's not an simple and 5 minutes task since it needs a revisiting of all callers first followed by rectifying the API itself. > >> Otherwise, I do not think that removing the "if (!irq)" hunk is safe. no ? > > > > Of course it isn't... -- With Best Regards, Andy Shevchenko
