[PATCH] drm/nouveau: fix incorrect FB_BACKLIGHT usage in Kconfig

[Randy Dunlap]

On 12/28/18 7:15 AM, Bartlomiej Zolnierkiewicz wrote:
> Making FB_BACKLIGHT tristate by commit b4a1ed0cd18b ("fbdev:
> make FB_BACKLIGHT a tristate") caused unmet dependencies in
> some configurations:
> 
> WARNING: unmet direct dependencies detected for FB_BACKLIGHT
>   Depends on [m]: HAS_IOMEM [=y] && FB [=m]
>   Selected by [y]:
>   - DRM_NOUVEAU [=y] && HAS_IOMEM [=y] && DRM [=y] && PCI [=y] && MMU [=y] && DRM_NOUVEAU_BACKLIGHT [=y]
>   Selected by [m]:
>   - FB_NVIDIA [=m] && HAS_IOMEM [=y] && FB [=m] && PCI [=y] && FB_NVIDIA_BACKLIGHT [=y]
> 
> Fix it by making DRM_NOUVEAU select BACKLIGHT_CLASS_DEVICE and
> BACKLIGHT_LCD_SUPPORT instead of FB_BACKLIGHT.
> 
> Fixes: b4a1ed0cd18b ("fbdev: make FB_BACKLIGHT a tristate")
> Reported-by: Randy Dunlap <rdunlap at infradead.org>
> Cc: Rob Clark <robdclark at gmail.com>
> Cc: Arnd Bergmann <arnd at arndb.de>
> Cc: Ben Skeggs <bskeggs at redhat.com>
> Cc: David Airlie <airlied at linux.ie>
> Cc: Daniel Vetter <daniel at ffwll.ch>
> Cc: Stephen Rothwell <sfr at canb.auug.org.au>
> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie at samsung.com>

Works for me.  Thanks.

Acked-by: Randy Dunlap <rdunlap at infradead.org> # build-tested

> ---
> I would like to merge this patch through fbdev tree for v4.21
> (as it is needed to fix commit currently in fbdev tree).
> 
>  drivers/gpu/drm/nouveau/Kconfig |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> Index: b/drivers/gpu/drm/nouveau/Kconfig
> ===================================================================
> --- a/drivers/gpu/drm/nouveau/Kconfig	2018-11-30 11:46:55.716464505 +0100
> +++ b/drivers/gpu/drm/nouveau/Kconfig	2018-12-28 14:54:51.655965845 +0100
> @@ -4,7 +4,8 @@ config DRM_NOUVEAU
>          select FW_LOADER
>  	select DRM_KMS_HELPER
>  	select DRM_TTM
> -	select FB_BACKLIGHT if DRM_NOUVEAU_BACKLIGHT
> +	select BACKLIGHT_CLASS_DEVICE if DRM_NOUVEAU_BACKLIGHT
> +	select BACKLIGHT_LCD_SUPPORT if DRM_NOUVEAU_BACKLIGHT
>  	select ACPI_VIDEO if ACPI && X86 && BACKLIGHT_CLASS_DEVICE && INPUT
>  	select X86_PLATFORM_DEVICES if ACPI && X86
>  	select ACPI_WMI if ACPI && X86
> 


-- 
~Randy