From: Arnd Bergmann <arnd@xxxxxxxx> The i915 driver can use the backlight subsystem as an option, and usually selects it when CONFIG_ACPI is set. However it is possible to configure a kernel with modular backlight classdev support and a built-in i915 driver, which leads to a linker error: drivers/gpu/drm/i915/display/intel_panel.o: In function `intel_backlight_device_register': intel_panel.c:(.text+0x2f58): undefined reference to `backlight_device_register' drivers/gpu/drm/i915/display/intel_panel.o: In function `intel_backlight_device_unregister': intel_panel.c:(.text+0x2fe4): undefined reference to `backlight_device_unregister' Change i915 to just 'depends on' for both BACKLIGHT_CLASS_DEVICE and ACPI_VIDEO, which avoids a lot of the problems. Link: https://lore.kernel.org/all/20200108140227.3976563-1-arnd@xxxxxxxx/ Link: https://lore.kernel.org/all/20200417155553.675905-1-arnd@xxxxxxxx/ Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- This change depends on cleaning up drivers/video/fbdev to no longer 'select' I2C and BACKLIGHT_CLASS_DEVICE, otherwise it causes dependency loops. --- drivers/gpu/drm/i915/Kconfig | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig index 84b6fc70cbf5..f427e6d50d9b 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 || !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 BACKLIGHT_CLASS_DEVICE if ACPI - select INPUT if ACPI - select ACPI_VIDEO if ACPI - select ACPI_BUTTON if ACPI select SYNC_FILE select IOSF_MBI select CRC32 -- 2.29.2
