• Arnd Bergmann's avatar
    drm/panel: rm68200: Add backlight dependency · a8efe516
    Arnd Bergmann authored
    Like many other panel drivers, this one fails to build when backlight
    support is disabled:
    
    drivers/gpu/drm/panel/panel-raydium-rm68200.o: In function `rm68200_probe':
    panel-raydium-rm68200.c:(.text+0x14a): undefined reference to `devm_of_find_backlight'
    
    This adds the appropriate dependency.
    
    Note that while include/linux/backlight.h provides a stub inline when
    backlight support is not enabled, this isn't enough to deal with the
    case where backlight support is built as a module but the panel driver
    is built-in, in which case linking will still fail as above.
    
    One way to avoid this is to add a dependency such as this:
    
            depends on BACKLIGHT_CLASS_DEVICE || BACKLIGHT_CLASS_DEVICE=n
    
    but that is rather complex and misses the point that the panel support
    is mostly useless without backlight support.
    
    Fixes: 2b7ed18b
    
     ("drm/panel: Add support for Raydium RM68200 panel driver")
    Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
    [treding@nvidia.com: clarify the need for the dependency]
    Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
    Link: https://patchwork.freedesktop.org/patch/msgid/20180313210015.3344380-1-arnd@arndb.de
    a8efe516