Re: [PATCH] nouveau: make backlight support non optional

[Arnd Bergmann <arnd@kernel.org>]

On Sat, Jul 24, 2021 at 4:14 PM Karol Herbst <kherbst@redhat.com> wrote:
>
> we use the MXM_WMI in code. We also have to keep arm in mind and not
> break stuff there. So I will try to play around with your changes and
> see how that goes.

Ok, should find any randconfig build failures for arm, arm64 or x86 over the
weekend. I also this on linux-next today

ld: drivers/gpu/drm/i915/display/intel_panel.o: in function
`intel_backlight_device_register':
intel_panel.c:(.text+0x2804): undefined reference to `backlight_device_register'
ld: intel_panel.c:(.text+0x284e): undefined reference to
`backlight_device_register'
ld: drivers/gpu/drm/i915/display/intel_panel.o: in function
`intel_backlight_device_unregister':
intel_panel.c:(.text+0x28b1): undefined reference to
`backlight_device_unregister'

and I added this same thing there to see how it goes:

diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
index 87825d36335b..69c6b7aec49e 100644
--- a/drivers/gpu/drm/i915/Kconfig
+++ b/drivers/gpu/drm/i915/Kconfig
@@ -3,6 +3,8 @@ config DRM_I915
        tristate "Intel 8xx/9xx/G3x/G4x/HD Graphics"
        depends on DRM
        depends on X86 && PCI
+       depends on ACPI_VIDEO || !ACPI
+       depends on BACKLIGHT_CLASS_DEVICE
        select INTEL_GTT
        select INTERVAL_TREE
        # we need shmfs for the swappable backing store, and in particular
@@ -16,10 +18,6 @@ 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 DRM_I915_BACKLIGHT if ACPI
-       select INPUT if ACPI
-       select ACPI_VIDEO if ACPI
-       select ACPI_BUTTON if ACPI
        select SYNC_FILE
        select IOSF_MBI
        select CRC32
@@ -64,13 +62,7 @@ config DRM_I915_FORCE_PROBE
          Use "*" to force probe the driver for all known devices.

 config DRM_I915_BACKLIGHT
-       tristate "Control backlight support"
-       depends on DRM_I915
-       default DRM_I915
-       select BACKLIGHT_CLASS_DEVICE
-       help
-          Say Y here if you want to control the backlight of your display
-          (e.g. a laptop panel).
+       def_tristate DRM_I915

 config DRM_I915_CAPTURE_ERROR
        bool "Enable capturing GPU state following a hang"