On Thu, 23 Feb 2023 18:37:01 +0000, Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote: > > Hi Marc, > > On 2/14/23 11:56, Marc Zyngier wrote: > > On Tue, 14 Feb 2023 18:30:54 +0000, > > Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote: > >> > >> > >> > >> On 2/13/23 00:05, Arnd Bergmann wrote: > >>> On Mon, Feb 13, 2023, at 05:15, Randy Dunlap wrote: > >>>> IRQ_DOMAIN is a hidden (not user visible) symbol. Users cannot set > >>>> it directly thru "make *config", so drivers should select it instead > >>>> of depending on it if they need it. > >>>> Relying on it being set for a dependency is risky. > >>>> > >>>> Consistently using "select" or "depends on" can also help reduce > >>>> Kconfig circular dependency issues. > >>>> > >>>> IRQ_DOMAIN is selected 109 times and is depended on 3 times in > >>>> current linux-next. Eliminate the uses of "depends on" by > >>>> converting them to "select". > >>>> > >>>> [PATCH 1/3] extcon: max8997: select IRQ_DOMAIN instead of depending on it > >>>> [PATCH 2/3] of: OF_IRQ: select IRQ_DOMAIN instead of depending on it > >>>> [PATCH 3/3] rtc: mt6397: select IRQ_DOMAIN instead of depending on it > >>> > >>> From a Kconfig perspective, your reasoning makes a lot of sense. > >>> > >>> Looking at the bigger picture, I wonder if we should just remove the > >>> option and make it unconditional. It is enabled in ever architecture > >>> defconfig other than alpha and sparc, and it's selected by a lot of > >>> very common options such as I2C, GENERIC_MSI_IRQ, GENERIC_IRQ_CHIP, > >>> and PCI_HOST_GENERIC. Enabling the option on Alpha grows the kernel > >>> image from 9010KB to 9023KB, or on m68k Coldfire from 3346KB to > >>> 3351KB. > >> > >> Marc, what do you think about this suggestion? > > > > Seems sensible enough to me. > > > > I'd also get rid of the IRQ_DOMAIN_HIERARCHY option, which is used by > > a ton of things. Architectures that are not using it are either dead, > > or at least terminally comatose. > > > > I'm half-tempted to put the following patch into -next. Maybe after > > -rc1 though. And then the option can go as well. > > > > M. > > What is this patch based on? It doesn't apply cleanly to current linux-next. Not very surprising, I usually base my stuff on a stable rc tag. But in this instance, it may have been based on whatever was in my sandbox at that point in time, and subsequently discarded. > I made a similar patch (to linux-next) that drops the IRQ_DOMAIN_HIERARCHY > option and converts its dependent code to always on. > It has been built (multiple randconfigs) on all ARCHes (except hexagon), > both 32-bit and 64-bit where applicable (not that it should matter here). > > But yes, let's plan to get one of these patches in soon (after -rc1). Please send it based on -rc1 once it is out, and I'll be happy to stick that in -next for further simmering. Thanks, M. -- Without deviation from the norm, progress is not possible.
