Re: [PATCH -next] drm/rockchip: Fix Kconfig dependencies

[Andy Yan]

Hi Zhijie:

On 5/7/22 09:00, Ren Zhijie wrote:
> If CONFIG_ROCKCHIP_ANALOGIX_DP is not set, the rockchip drm driver
> will fail to link:
>
> drivers/gpu/drm/rockchip/cdn-dp-core.o: In function `cdn_dp_connector_mode_valid':
> cdn-dp-core.c:(.text+0x1e1): undefined reference to `drm_dp_bw_code_to_link_rate'
> cdn-dp-core.c:(.text+0x1f4): undefined reference to `drm_dp_bw_code_to_link_rate'
> drivers/gpu/drm/rockchip/cdn-dp-core.o: In function `cdn_dp_pd_event_work':
> cdn-dp-core.c:(.text+0x138e): undefined reference to `drm_dp_channel_eq_ok'
> drivers/gpu/drm/rockchip/cdn-dp-reg.o: In function `cdn_dp_train_link':
> cdn-dp-reg.c:(.text+0xd5a): undefined reference to `drm_dp_bw_code_to_link_rate'
>
> The problem is that the DP-helper module has been replaced by the display-helper module.
> So the driver have to select it.
>
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Fixes: 1e0f66420b13("drm/display: Introduce a DRM display-helper module")
> Signed-off-by: Ren Zhijie <renzhijie2@xxxxxxxxxx>
> ---
>   drivers/gpu/drm/rockchip/Kconfig | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/rockchip/Kconfig b/drivers/gpu/drm/rockchip/Kconfig
> index 5afab49dc4f2..eb9ffa9e357d 100644
> --- a/drivers/gpu/drm/rockchip/Kconfig
> +++ b/drivers/gpu/drm/rockchip/Kconfig
> @@ -47,6 +47,8 @@ config ROCKCHIP_ANALOGIX_DP
>   config ROCKCHIP_CDN_DP
>   	bool "Rockchip cdn DP"
>   	depends on EXTCON=y || (EXTCON=m && DRM_ROCKCHIP=m)
> +	select DRM_DISPLAY_HELPER
> +	select DRM_DISPLAY_DP_HELPER


There are two dp(ANALOGIX_DP and CDN_DP) at rockchip drm mainline,

for a totally cleanup and alignment, I think it's better to remove 
"select DRM_DISPLAY_HELPER if ROCKCHIP_ANALOGIX_DP" under DRM_ROCKCHIP  
at the head,

and separately add the select for ROCKCHIP_ANALOGIX_DP and ROCKCHIP_CDN_DP.

>   	help
>   	  This selects support for Rockchip SoC specific extensions
>   	  for the cdn DP driver. If you want to enable Dp on