[PATCH] drm: rcar-du: fix linker undefined references

[Laurent Pinchart]

Hi Randy,

Thank you for the patch.

On Fri, Apr 23, 2021 at 02:37:27PM -0700, Randy Dunlap wrote:
> When DRM_RCAR_DU=y and DRM_RCAR_LVDS=m, there are several build errors
> as reported by 'kernel test robot'. These can be corrected by changing
> "imply" to "select".
> 
> In looking at this, the same problem (build errors) happens when
> DRM_RCAR_DU=y and DRM_RCAR_CMM=m, so again change the "imply" to
> "select" here as well.
> 
> These 2 changes fix the following 8 build/link errors:
> 
> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_enable':
> rcar_du_crtc.c:(.text+0x1be8): undefined reference to `rcar_lvds_clk_enable'
> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_disable':
> rcar_du_crtc.c:(.text+0x2438): undefined reference to `rcar_lvds_clk_disable'
> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_drv.o: in function `rcar_du_init':
> rcar_du_drv.c:(.init.text+0x14): undefined reference to `rcar_du_of_init'
> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_encoder.o: in function `rcar_du_encoder_init':
> rcar_du_encoder.c:(.text+0x1d4): undefined reference to `rcar_lvds_dual_link'
> 
> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_cmm_setup':
> rcar_du_crtc.c:(.text+0x380): undefined reference to `rcar_cmm_setup'
> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_enable':
> rcar_du_crtc.c:(.text+0x1c08): undefined reference to `rcar_cmm_enable'
> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_disable':
> rcar_du_crtc.c:(.text+0x231c): undefined reference to `rcar_cmm_disable'
> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_kms.o: in function `rcar_du_modeset_init':
> rcar_du_kms.c:(.text+0xd08): undefined reference to `rcar_cmm_init'
> 
> Fixes: e08e934d6c28 ("drm: rcar-du: Add support for CMM")
> Fixes: 02f2b30032c1 ("drm: rcar-du: lvds: Add API to enable/disable clock output")
> Signed-off-by: Randy Dunlap <rdunlap at infradead.org>
> Reported-by: kernel test robot <lkp at intel.com>
> Cc: Masahiro Yamada <masahiroy at kernel.org>
> Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Cc: Kieran Bingham <kieran.bingham+renesas at ideasonboard.com>
> Cc: dri-devel at lists.freedesktop.org
> Cc: linux-renesas-soc at vger.kernel.org
> Cc: Jacopo Mondi <jacopo+renesas at jmondi.org>
> ---
>  drivers/gpu/drm/rcar-du/Kconfig |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> --- linux-next-20210420.orig/drivers/gpu/drm/rcar-du/Kconfig
> +++ linux-next-20210420/drivers/gpu/drm/rcar-du/Kconfig
> @@ -4,8 +4,8 @@ config DRM_RCAR_DU
>  	depends on DRM && OF
>  	depends on ARM || ARM64
>  	depends on ARCH_RENESAS || COMPILE_TEST
> -	imply DRM_RCAR_CMM
> -	imply DRM_RCAR_LVDS
> +	select DRM_RCAR_CMM
> +	select DRM_RCAR_LVDS

No all platforms that integrate a DU have CMM and/or LVDS support, so we
shouldn't select the automatically.

Would

	depends on DRM_RCAR_CMM || DRM_RCAR_CMM=n
	depends on DRM_RCAR_LVDS || DRM_RCAR_LVDS=n

work ? I thought that's what "imply" meant, but it seems I got it wrong.

>  	select DRM_KMS_HELPER
>  	select DRM_KMS_CMA_HELPER
>  	select DRM_GEM_CMA_HELPER

-- 
Regards,

Laurent Pinchart