[PATCH] drm: rcar_du: DRM_RCAR_DU optionally depends on RCAR_MIPI_DSI

[Randy Dunlap]

When CONFIG_DRM_RCAR_DU=y and CONFIG_DRM_RCAR_MIPI_DSI=m, calls
from the builtin driver to the mipi driver fail due to linker
errors.
Since the RCAR_MIPI_DSI driver is not always required, fix the
build error by making DRM_RCAR_DU optionally depend on the
RCAR_MIPI_DSI Kconfig symbol. This prevents the problematic
kconfig combination without requiring that RCAR_MIPI_DSI always
be enabled.

aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_enable':
rcar_du_crtc.c:(.text+0x3a18): undefined reference to `rcar_mipi_dsi_pclk_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+0x47cc): undefined reference to `rcar_mipi_dsi_pclk_disable'

Fixes: 957fe62d7d15 ("drm: rcar-du: Fix DSI enable & disable sequence")
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Tomi Valkeinen <tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>
Cc: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
Cc: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
Cc: LUU HOAI <hoai.luu.ub@xxxxxxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-renesas-soc@xxxxxxxxxxxxxxx
Cc: David Airlie <airlied@xxxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
---
 drivers/gpu/drm/rcar-du/Kconfig |    1 +
 1 file changed, 1 insertion(+)

diff -- a/drivers/gpu/drm/rcar-du/Kconfig b/drivers/gpu/drm/rcar-du/Kconfig
--- a/drivers/gpu/drm/rcar-du/Kconfig
+++ b/drivers/gpu/drm/rcar-du/Kconfig
@@ -4,6 +4,7 @@ config DRM_RCAR_DU
 	depends on DRM && OF
 	depends on ARM || ARM64
 	depends on ARCH_RENESAS || COMPILE_TEST
+	depends on DRM_RCAR_MIPI_DSI || DRM_RCAR_MIPI_DSI=n
 	select DRM_KMS_HELPER
 	select DRM_GEM_DMA_HELPER
 	select VIDEOMODE_HELPERS