Hi Jani, On 9/12/23 07:52, Randy Dunlap wrote: > > > On 9/12/23 00:47, Jani Nikula wrote: >> On Mon, 11 Sep 2023, Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote: >>> On 9/10/23 19:11, Stephen Rothwell wrote: >>>> Hi all, >>>> >>>> Please do *not* include material destined for v6.7 in your linux-next >>>> included branches until *after* v6.6-rc1 has been released. Also, >>>> do *not* rebase your linu-next included branches onto v6.5. >>>> >>>> Changes since 20230908: >>>> >>>> Non-merge commits (relative to Linus' tree): 643 >>>> 614 files changed, 227990 insertions(+), 9502 deletions(-) >>>> >>>> ---------------------------------------------------------------------------- >>> >>> on x86_64: >>> >>> # CONFIG_ACPI is not set >>> CONFIG_DRM_I915=y >>> CONFIG_BACKLIGHT_CLASS_DEVICE=m >>> >>> I915 selects BACKLIGHT_CLASS_DEVICE if ACPI is set. >>> >>> ld: drivers/gpu/drm/i915/display/intel_backlight.o: in function `intel_backlight_device_register': >>> intel_backlight.c:(.text+0x4988): undefined reference to `backlight_device_get_by_name' >>> ld: intel_backlight.c:(.text+0x4a1b): undefined reference to `backlight_device_register' >>> ld: drivers/gpu/drm/i915/display/intel_backlight.o: in function `intel_backlight_device_unregister': >>> intel_backlight.c:(.text+0x4b56): undefined reference to `backlight_device_unregister' >> >> This comes up periodically. The fix is for i915 to depend on backlight, >> but it's not possible to fix just i915, as it'll lead to circular deps >> unless *all* select backlight is switched to depend on backlight. >> >> I've gone through it once [1], and not keen on doing it again unless >> there's buy-in. >> >> IS_REACHABLE() is often suggested as a workaround, but I think it's just >> plain wrong. i915=y backlight=m is not a configuration that makes >> sense. Kernel configuration is hard enough, there's no point in allowing >> dumb configs that just silently don't work. >> > > Yes, IS_REACHABLE() is just fugly nonsense. > > Thanks for the reminder of your attempt(s). > >> >> BR, >> Jani. >> >> >> [1] https://lore.kernel.org/r/1413580403-16225-1-git-send-email-jani.nikula@xxxxxxxxx I did a partial patch series (eliminated the I915 problems with 9 patches, without build testing -- only kconfig testing -- so more changes may be needed), then I looked at your patch [1] above. I like it but even if Tomi and Daniel didn't have problems with it, I am concerned that it would cause problems with existing working .config files. Still, something should be done about the mixed usage of select and depends on for BACKLIGHT_CLASS_DEVICE (et al). thanks. -- ~Randy
