tree 1692a9a68bd7bfb8386b03777bd1912092f80312
parent c91bb237728fea4eb7f73f6e4782e6e3358b825e
author Arnd Bergmann <arnd@arndb.de> 1578152568 +0100
committer Arnd Bergmann <arnd@arndb.de> 1635336995 +0200

[v2] i915: fix backlight configuration issue

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@arndb.de/
Link: https://lore.kernel.org/all/20200417155553.675905-1-arnd@arndb.de/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
This change depends on cleaning up drivers/video/fbdev to no longer
'select' I2C and BACKLIGHT_CLASS_DEVICE, otherwise it causes
dependency loops.