[PATCH v2 2/3] drm/fbdev: Select FB_CORE dependency for fbdev on DMA and TTM

[LEROY Christophe]

Le 12/12/2024 à 11:04, Thomas Zimmermann a écrit :
> Select FB_CORE if GEM's DMA and TTM implementations support fbdev
> emulation. Fixes linker errors about missing symbols from the fbdev
> subsystem.
> 
> Also see [1] for a related SHMEM fix.
> 
> Fixes: dadd28d4142f ("drm/client: Add client-lib module")
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> Link: https://patchwork.freedesktop.org/series/141411/ # 1
> ---
>   drivers/gpu/drm/Kconfig | 2 ++
>   1 file changed, 2 insertions(+)

Build fails which pmac32_defconfig :

   LD      .tmp_vmlinux1
powerpc64-linux-ld: drivers/macintosh/via-pmu-backlight.o: in function 
`pmu_backlight_init':
via-pmu-backlight.c:(.init.text+0xc0): undefined reference to 
`backlight_device_register'
make[2]: *** [scripts/Makefile.vmlinux:77: vmlinux] Error 1
make[1]: *** [/home/chleroy/linux-powerpc/Makefile:1225: vmlinux] Error 2



> 
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 9abb41da4e3a..55ce61a46984 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -293,6 +293,7 @@ config DRM_TTM_HELPER
>   	tristate
>   	depends on DRM
>   	select DRM_TTM
> +	select FB_CORE if DRM_FBDEV_EMULATION
>   	select FB_SYSMEM_HELPERS_DEFERRED if DRM_FBDEV_EMULATION
>   	help
>   	  Helpers for ttm-based gem objects
> @@ -300,6 +301,7 @@ config DRM_TTM_HELPER
>   config DRM_GEM_DMA_HELPER
>   	tristate
>   	depends on DRM
> +	select FB_CORE if DRM_FBDEV_EMULATION
>   	select FB_DMAMEM_HELPERS_DEFERRED if DRM_FBDEV_EMULATION
>   	help
>   	  Choose this if you need the GEM DMA helper functions