| Message ID | 20221004102837.12181-1-jirislaby@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] drm/i915/display: fix randconfig build | expand |
On 04. 10. 22, 12:52, Jani Nikula wrote: > On Tue, 04 Oct 2022, "Jiri Slaby (SUSE)" <jirislaby@kernel.org> wrote: >> When DRM_I915=y and BACKLIGHT_CLASS_DEVICE=m, the build fails: >> ld: drivers/gpu/drm/i915/display/intel_backlight.o: in function `intel_backlight_device_register': >> intel_backlight.c:(.text+0x5587): undefined reference to `backlight_device_get_by_name' >> >> ld: drivers/gpu/drm/i915/display/intel_backlight.o: in function `intel_backlight_device_unregister': >> intel_backlight.c:(.text+0x576e): undefined reference to `backlight_device_unregister' >> >> To fix this, use IS_REACHABLE(), not IS_ENABLED() in backlight. That is, >> with the above config, backlight support is disabled. > > So I don't want this. I'll take a patch that fixes the dependencies to > block DRM_I915=y and BACKLIGHT_CLASS_DEVICE=m. Nobody wants that combo, > and IMO using IS_REACHABLE() is a workaround to hide a broken config > under the carpet. > > The right thing to do is > > config DRM_I915 > depends on BACKLIGHT_CLASS_DEVICE || BACKLIGHT_CLASS_DEVICE=n. > > We're selecting BACKLIGHT_CLASS_DEVICE because almost everyone else is > too, and a combo of selecting and depending leads to circular > dependencies. But depending is the right fix. I'm not sure what should I do now. If I do: --- a/drivers/gpu/drm/i915/Kconfig +++ b/drivers/gpu/drm/i915/Kconfig @@ -4,6 +4,7 @@ config DRM_I915 depends on DRM depends on X86 && PCI depends on !PREEMPT_RT + depends on (BACKLIGHT_CLASS_DEVICE && ACPI) || (BACKLIGHT_CLASS_DEVICE=n && ACPI=n) select INTEL_GTT if X86 select INTERVAL_TREE # we need shmfs for the swappable backing store, and in particular @@ -21,7 +22,6 @@ config DRM_I915 select IRQ_WORK # i915 depends on ACPI_VIDEO when ACPI is enabled # but for select to work, need to select ACPI_VIDEO's dependencies, ick - select BACKLIGHT_CLASS_DEVICE if ACPI select INPUT if ACPI select X86_PLATFORM_DEVICES if ACPI select ACPI_WMI if ACPI I get: drivers/gpu/drm/i915/Kconfig:2:error: recursive dependency detected! drivers/gpu/drm/i915/Kconfig:2: symbol DRM_I915 depends on BACKLIGHT_CLASS_DEVICE drivers/video/backlight/Kconfig:143: symbol BACKLIGHT_CLASS_DEVICE is selected by DRM_FSL_DCU drivers/gpu/drm/fsl-dcu/Kconfig:2: symbol DRM_FSL_DCU depends on COMMON_CLK drivers/clk/Kconfig:21: symbol COMMON_CLK is selected by X86_INTEL_QUARK arch/x86/Kconfig:633: symbol X86_INTEL_QUARK depends on X86_PLATFORM_DEVICES drivers/platform/x86/Kconfig:6: symbol X86_PLATFORM_DEVICES is selected by DRM_I915 Those dependencies are really cumbersome :/. > Documentation/kbuild/kconfig-language.rst: > > Note: > select should be used with care. select will force > a symbol to a value without visiting the dependencies. > By abusing select you are able to select a symbol FOO even > if FOO depends on BAR that is not set. > In general use select only for non-visible symbols > (no prompts anywhere) and for symbols with no dependencies. > That will limit the usefulness but on the other hand avoid > the illegal configurations all over. > > > BR, > Jani. > >> >> Cc: Jani Nikula <jani.nikula@linux.intel.com> >> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> >> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> >> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> >> Cc: David Airlie <airlied@gmail.com> >> Cc: Daniel Vetter <daniel@ffwll.ch> >> Cc: intel-gfx@lists.freedesktop.org >> Cc: dri-devel@lists.freedesktop.org >> Reported-by: Martin Liška <mliska@suse.cz> >> Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> >> --- >> drivers/gpu/drm/i915/display/intel_backlight.c | 2 +- >> drivers/gpu/drm/i915/display/intel_backlight.h | 2 +- >> 2 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/i915/display/intel_backlight.c b/drivers/gpu/drm/i915/display/intel_backlight.c >> index beba39a38c87..c1ba68796b6d 100644 >> --- a/drivers/gpu/drm/i915/display/intel_backlight.c >> +++ b/drivers/gpu/drm/i915/display/intel_backlight.c >> @@ -825,7 +825,7 @@ void intel_backlight_enable(const struct intel_crtc_state *crtc_state, >> mutex_unlock(&dev_priv->display.backlight.lock); >> } >> >> -#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE) >> +#if IS_REACHABLE(CONFIG_BACKLIGHT_CLASS_DEVICE) >> static u32 intel_panel_get_backlight(struct intel_connector *connector) >> { >> struct drm_i915_private *dev_priv = to_i915(connector->base.dev); >> diff --git a/drivers/gpu/drm/i915/display/intel_backlight.h b/drivers/gpu/drm/i915/display/intel_backlight.h >> index 339643f63897..207fe1c613d8 100644 >> --- a/drivers/gpu/drm/i915/display/intel_backlight.h >> +++ b/drivers/gpu/drm/i915/display/intel_backlight.h >> @@ -36,7 +36,7 @@ u32 intel_backlight_invert_pwm_level(struct intel_connector *connector, u32 leve >> u32 intel_backlight_level_to_pwm(struct intel_connector *connector, u32 level); >> u32 intel_backlight_level_from_pwm(struct intel_connector *connector, u32 val); >> >> -#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE) >> +#if IS_REACHABLE(CONFIG_BACKLIGHT_CLASS_DEVICE) >> int intel_backlight_device_register(struct intel_connector *connector); >> void intel_backlight_device_unregister(struct intel_connector *connector); >> #else /* CONFIG_BACKLIGHT_CLASS_DEVICE */ >
diff --git a/drivers/gpu/drm/i915/display/intel_backlight.c b/drivers/gpu/drm/i915/display/intel_backlight.c index beba39a38c87..c1ba68796b6d 100644 --- a/drivers/gpu/drm/i915/display/intel_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_backlight.c @@ -825,7 +825,7 @@ void intel_backlight_enable(const struct intel_crtc_state *crtc_state, mutex_unlock(&dev_priv->display.backlight.lock); } -#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE) +#if IS_REACHABLE(CONFIG_BACKLIGHT_CLASS_DEVICE) static u32 intel_panel_get_backlight(struct intel_connector *connector) { struct drm_i915_private *dev_priv = to_i915(connector->base.dev); diff --git a/drivers/gpu/drm/i915/display/intel_backlight.h b/drivers/gpu/drm/i915/display/intel_backlight.h index 339643f63897..207fe1c613d8 100644 --- a/drivers/gpu/drm/i915/display/intel_backlight.h +++ b/drivers/gpu/drm/i915/display/intel_backlight.h @@ -36,7 +36,7 @@ u32 intel_backlight_invert_pwm_level(struct intel_connector *connector, u32 leve u32 intel_backlight_level_to_pwm(struct intel_connector *connector, u32 level); u32 intel_backlight_level_from_pwm(struct intel_connector *connector, u32 val); -#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE) +#if IS_REACHABLE(CONFIG_BACKLIGHT_CLASS_DEVICE) int intel_backlight_device_register(struct intel_connector *connector); void intel_backlight_device_unregister(struct intel_connector *connector); #else /* CONFIG_BACKLIGHT_CLASS_DEVICE */
When DRM_I915=y and BACKLIGHT_CLASS_DEVICE=m, the build fails: ld: drivers/gpu/drm/i915/display/intel_backlight.o: in function `intel_backlight_device_register': intel_backlight.c:(.text+0x5587): undefined reference to `backlight_device_get_by_name' ld: drivers/gpu/drm/i915/display/intel_backlight.o: in function `intel_backlight_device_unregister': intel_backlight.c:(.text+0x576e): undefined reference to `backlight_device_unregister' To fix this, use IS_REACHABLE(), not IS_ENABLED() in backlight. That is, with the above config, backlight support is disabled. Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: David Airlie <airlied@gmail.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: intel-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org Reported-by: Martin Liška <mliska@suse.cz> Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> --- drivers/gpu/drm/i915/display/intel_backlight.c | 2 +- drivers/gpu/drm/i915/display/intel_backlight.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)