Commit 72fee6b0a3a4 ("fbdev: Restrict FB_SH_MOBILE_LCDC to SuperH") disabled availablity of the SH_MOBILE_LCDC driver on the RENESAS arch. This innocent change has a significant side-effect on the ARM's multi_v7_defconfig, because FB_BACKLIGHT symbol is no longer selected, what in turn leaves BACKLIGHT_CLASS_DEVICE symbol selected only as a module. The latter disables some backlight related code in the DRM core, because the DRM core is set to be compiled-in in this defconfig. This leaves all DRM display panels without integrated backlight control, even if the needed modules have been properly loaded and probed. Fix this by selecting BACKLIGHT_CLASS_DEVICE to be compiled-in in multi_v7_defconfig. Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> --- arch/arm/configs/multi_v7_defconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig index 8f7445729cd0..b2955dcb5a53 100644 --- a/arch/arm/configs/multi_v7_defconfig +++ b/arch/arm/configs/multi_v7_defconfig @@ -777,6 +777,7 @@ CONFIG_FB_EFI=y CONFIG_FB_WM8505=y CONFIG_FB_SH_MOBILE_LCDC=y CONFIG_FB_SIMPLE=y +CONFIG_BACKLIGHT_CLASS_DEVICE=y CONFIG_BACKLIGHT_PWM=y CONFIG_BACKLIGHT_AS3711=y CONFIG_BACKLIGHT_GPIO=y -- 2.34.1