Le 06/10/2022 à 16:24, Alan Stern a écrit : > On Thu, Oct 06, 2022 at 02:01:57PM +0000, Christophe Leroy wrote: >> >> >> Le 06/10/2022 à 15:50, Alan Stern a écrit : >>> On Thu, Oct 06, 2022 at 07:15:44AM +0200, Christophe Leroy wrote: >>>> NO_IRQ is used to check the return of irq_of_parse_and_map(). >>>> >>>> On some architecture NO_IRQ is 0, on other architectures it is -1. >>>> >>>> irq_of_parse_and_map() returns 0 on error, independent of NO_IRQ. >>> >>> This isn't clear. Does absence of an irq count as an error? In other >>> words, will irq_of_parse_and_map() sometimes return 0 and other times >>> return NO_IRQ? What about architectures on which 0 is a valid irq >>> number? >> >> NO_IRQ doesn't exist anywhere in core functions. Only some drivers and >> some architectures have relics of it. >> >> irq_of_parse_and_map() will always return 0 on error. >> >> 0 can't be a valid logical IRQ number. It may only be a valid hwirq >> number but it will always be translated to a non-zero logical irq number. >> >> I'm trying to get rid of NO_IRQ completely in powerpc code, therefore >> trying to clean-up all drivers used by powerpc architecture. >> >> Long time ago Linus advocated for not using NO_IRQ, see >> https://lkml.org/lkml/2005/11/21/221 > > Okay, good. Please resubmit the patch and include some of these things > in the patch description. I sent v2 with more details in the commit message. Thanks Christophe
