On Tuesday, November 8, 2016 10:46:07 AM CET Ilia Mirkin wrote: > > diff --git a/drivers/gpu/drm/nouveau/Kconfig b/drivers/gpu/drm/nouveau/Kconfig > > index 78631fb61adf..715cd6f4dc31 100644 > > --- a/drivers/gpu/drm/nouveau/Kconfig > > +++ b/drivers/gpu/drm/nouveau/Kconfig > > @@ -46,6 +46,14 @@ config NOUVEAU_DEBUG > > The paranoia and spam levels will add a lot of extra checks which > > may potentially slow down driver operation. > > > > +config DRM_NOUVEAU_LED > > + bool "Support for logo LED" > > + depends on DRM_NOUVEAU && LEDS_CLASS > > + depends on !(DRM_NOUVEAU=y && LEDS_CLASS=m) > > + help > > + Say Y here to enabling controlling the brightness of the > > + LED behind NVIDIA logo on certain Titan cards. > > This is a very odd restriction... could this be written as > > depends on DRM_NOUVEAU > select LEDS_CLASS > > Or will that not flip the LEDS_CLASS from m to y in case > DRM_NOUVEAU=y? If not, is there a way to cause that to happen? Using 'select' on user-selectable symbols risks introducing circular dependencies. > Separately, perhaps we should just drop this LEDS_CLASS select into > DRM_NOUVEAU? We've tended to avoid adding tons of options. My first attempt was to add "depends on LEDS_CLASS || !LEDS_CLASS" to DRM_NOUVEAU, which led to one long circle: drivers/usb/Kconfig:39:error: recursive dependency detected! For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/usb/Kconfig:39: symbol USB is selected by MOUSE_APPLETOUCH For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/input/mouse/Kconfig:187: symbol MOUSE_APPLETOUCH depends on INPUT For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/input/Kconfig:8: symbol INPUT is selected by VT For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/tty/Kconfig:12: symbol VT is selected by FB_STI For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/video/fbdev/Kconfig:669: symbol FB_STI depends on FB For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/video/fbdev/Kconfig:5: symbol FB is selected by DRM_KMS_FB_HELPER For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/gpu/drm/Kconfig:42: symbol DRM_KMS_FB_HELPER depends on DRM_KMS_HELPER For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/gpu/drm/Kconfig:36: symbol DRM_KMS_HELPER is selected by DRM_NOUVEAU For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/gpu/drm/nouveau/Kconfig:1: symbol DRM_NOUVEAU depends on LEDS_CLASS For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/leds/Kconfig:16: symbol LEDS_CLASS is selected by OMAP_DEBUG_LEDS For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" arch/arm/plat-omap/Kconfig:19: symbol OMAP_DEBUG_LEDS depends on NEW_LEDS For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/leds/Kconfig:8: symbol NEW_LEDS is selected by ATH9K_HTC For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/net/wireless/ath/ath9k/Kconfig:158: symbol ATH9K_HTC depends on USB Tue, 08 Nov 2016 11:49:44 +0100 build/0x3053A542_defconfig warnings drivers/usb/Kconfig:39:error: recursive dependency detected! For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/usb/Kconfig:39: symbol USB is selected by MOUSE_APPLETOUCH For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/input/mouse/Kconfig:187: symbol MOUSE_APPLETOUCH depends on INPUT For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/input/Kconfig:8: symbol INPUT is selected by VT For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/tty/Kconfig:12: symbol VT is selected by FB_STI For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/video/fbdev/Kconfig:669: symbol FB_STI depends on FB For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/video/fbdev/Kconfig:5: symbol FB is selected by DRM_KMS_FB_HELPER For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/gpu/drm/Kconfig:42: symbol DRM_KMS_FB_HELPER depends on DRM_KMS_HELPER For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/gpu/drm/Kconfig:36: symbol DRM_KMS_HELPER is selected by DRM_NOUVEAU For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/gpu/drm/nouveau/Kconfig:1: symbol DRM_NOUVEAU depends on LEDS_CLASS For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/leds/Kconfig:16: symbol LEDS_CLASS is selected by OMAP_DEBUG_LEDS For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" arch/arm/plat-omap/Kconfig:19: symbol OMAP_DEBUG_LEDS depends on NEW_LEDS For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/leds/Kconfig:8: symbol NEW_LEDS is selected by ATH9K_HTC For a resolution refer to Documentation/kbuild/kconfig-language.txt subsection "Kconfig recursive dependency limitations" drivers/net/wireless/ath/ath9k/Kconfig:158: symbol ATH9K_HTC depends on USB The underlying problem is that we already have a number of other symbols that either have "depends on LEDS_CLASS" or "select LEDS_CLASS". To clean that up properly, we should either make the symbol itself hidden and only select it from other drivers, or use "depends on LEDS_CLASS" everywhere. Another option is to use the IS_REACHABLE() macro instead of IS_ENABLED() in the header file, to stub out the calls into the new file, but that can be a bit confusing. Arnd _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
