On Thu, Apr 16, 2020 at 08:51:14AM +0200, Daniel Vetter wrote: > On Wed, Apr 15, 2020 at 11:22 PM Arnd Bergmann wrote: > > On Wed, Apr 15, 2020 at 11:12 PM Laurent Pinchart wrote: > > > On Wed, Apr 15, 2020 at 09:07:14PM +0200, Arnd Bergmann wrote: > > > > On Wed, Apr 15, 2020 at 5:18 PM Arnd Bergmann <arnd@xxxxxxxx> wrote: > > > > > On Wed, Apr 15, 2020 at 4:13 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote: > > > > > > On Wed, Apr 15, 2020 at 3:47 PM Arnd Bergmann <arnd@xxxxxxxx> wrote: > > > > > > > On Tue, Apr 14, 2020 at 10:52 PM Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > > > > > > > > Doesn't "imply" mean it gets selected by default but can be manually > > > > > > > > disabled ? > > > > > > > > > > > > > > That may be what it means now (I still don't understand how it's defined > > > > > > > as of v5.7-rc1), but traditionally it was more like a 'select if all > > > > > > > dependencies are met'. > > > > > > > > > > > > That's still what it is supposed to mean right now ;-) > > > > > > Except that now it should correctly handle the modular case, too. > > > > > > > > > > Then there is a bug. If I run 'make menuconfig' now on a mainline kernel > > > > > and enable CONFIG_DRM_RCAR_DU, I can set > > > > > DRM_RCAR_CMM and DRM_RCAR_LVDS to 'y', 'n' or 'm' regardless > > > > > of whether CONFIG_DRM_RCAR_DU is 'm' or 'y'. The 'implies' > > > > > statement seems to be ignored entirely, except as reverse 'default' > > > > > setting. > > > > > > > > Here is another version that should do what we want and is only > > > > half-ugly. I can send that as a proper patch if it passes my testing > > > > and nobody hates it too much. > > > > > > This may be a stupid question, but doesn't this really call for fixing > > > Kconfig ? This seems to be such a common pattern that requiring > > > constructs similar to the ones below will be a never-ending chase of > > > offenders. > > > > Maybe, I suppose the hardest part here would be to come up with > > an appropriate name for the keyword ;-) > > > > Any suggestions? Would it make sense to fix the imply semantics ? Or are they use cases for the current behaviour of imply ? "recommend" could be another keyword. I think we should try to limit the number of keywords though, as it would otherwise become quite messy. > > This specific issue is fairly rare though, in most cases the dependencies > > are in the right order so a Kconfig symbol 'depends on' a second one > > when the corresponding loadable module uses symbols from that second > > module. The problem here is that the two are mixed up. > > > > The much more common problem is the one where one needs to > > wrong > > > > config FOO > > depends on BAR || !BAR > > > > To ensure the dependency is either met or BAR is disabled, but > > not FOO=y with BAR=m. If you have any suggestions for a keyword > > for that thing, we can clean up hundreds of such instances. > > Some ideas: > > config FOO > can use BAR > maybe BAR > optional BAR Another idea, depends optionally on BAR > We should probably double-check that this is only ever used for when > both FOO and BAR are tri-state, since without that it doesn't make > much sense. -- Regards, Laurent Pinchart
