[PATCH] drm/rockchip: add extcon dependency for DP

[Arnd Bergmann]

The newly added DP driver links against the extcon core, which fails when
extcon is a module and this driver is not:

drivers/gpu/drm/rockchip/cdn-dp-core.o: In function `cdn_dp_get_port_lanes':
cdn-dp-core.c:(.text.cdn_dp_get_port_lanes+0x24): undefined reference to `extcon_get_state'
cdn-dp-core.c:(.text.cdn_dp_get_port_lanes+0x44): undefined reference to `extcon_get_property'

Let's make Kconfig enforce correct behavior with a dependency.

Fixes: 1a0f7ed3abe2 ("drm/rockchip: cdn-dp: add cdn DP support for rk3399")
Signed-off-by: Arnd Bergmann <arnd at arndb.de>
---
 drivers/gpu/drm/rockchip/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/rockchip/Kconfig b/drivers/gpu/drm/rockchip/Kconfig
index ad31b3eb408f..0e4eb845cbb0 100644
--- a/drivers/gpu/drm/rockchip/Kconfig
+++ b/drivers/gpu/drm/rockchip/Kconfig
@@ -24,6 +24,7 @@ config ROCKCHIP_ANALOGIX_DP
 config ROCKCHIP_CDN_DP
         tristate "Rockchip cdn DP"
         depends on DRM_ROCKCHIP
+	depends on EXTCON
 	select SND_SOC_HDMI_CODEC if SND_SOC
         help
 	  This selects support for Rockchip SoC specific extensions
-- 
2.9.0