Hi Arnd, On Fri, Nov 29, 2024 at 10:23 AM Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Fri, Nov 29, 2024, at 09:44, Geert Uytterhoeven wrote: > > On Fri, Nov 29, 2024 at 9:25 AM Arnd Bergmann <arnd@xxxxxxxx> wrote: > >> On Fri, Nov 29, 2024, at 09:10, Herve Codina wrote: > >> I would write in two lines as > >> > >> depends on PCI > >> depends on OF_OVERLAY > >> > >> since OF_OVERLAY already depends on OF, that can be left out. > >> The effect is the same as your variant though. > > > > What about > > > > depends on OF > > select OF_OVERLAY > > > > as "OF" is a clear bus dependency, due to the driver providing an OF > > child bus (cfr. I2C or SPI bus controller drivers depending on I2C or > > SPI), and OF_OVERLAY is an optional software mechanism? > > OF_OVERLAY is currently a user visible option, so I think it's > intended to be used with 'depends on'. The only other callers > of this interface are the kunit test modules that just leave > out the overlay code if that is disabled. Indeed, there are no real upstream users of OF_OVERLAY left. Until commit 1760eb547276299a ("drm: rcar-du: Drop leftovers dependencies from Kconfig"), the rcar-lvds driver selected OF_OVERLAY to be able to fix up old DTBs. > If we decide to treat OF_OVERLAY as a library instead, it should > probably become a silent Kconfig option that gets selected by > all its users including the unit tests, and then we can remove > the #ifdef checks there. Yep. > Since OF_OVERLAY pulls in OF_DYNAMIC, I would still prefer that > to be a user choice. Silently enabling OF_OVERLAY definitely has > a risk of introducing regressions since it changes some of the > interesting code paths in the core, in particular it enables > reference counting in of_node_get(), which many drivers get wrong. Distro kernels will have to enable this anyway, if they want to support LAN966x... Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds