[PATCH] drm/bridge-connector: select DRM_DISPLAY_HELPER from DRM_BRIDGE_CONNECTOR

[Dmitry Baryshkov]

On Fri, Oct 18, 2024 at 03:08:45PM +0000, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd at arndb.de>
> 
> The imx display drivers use the new bridge connector helpers but don't
> explicitly select CONFIG_DRM_DISPLAY_HELPER, leading to a link failure
> in rare configurations:
> 
> ld.lld-20: error: undefined symbol: drm_bridge_connector_init
> >>> referenced by imx-ldb.c
> >>>               drivers/gpu/drm/imx/ipuv3/imx-ldb.o:(imx_ldb_bind) in archive vmlinux.a
> >>> referenced by parallel-display.c
> >>>               drivers/gpu/drm/imx/ipuv3/parallel-display.o:(imx_pd_bind) in archive vmlinux.a
> 
> Move DRM_BRIDGE_CONNECTOR out of the DRM_DISPLAY_HELPER block and
> instead select that symbol indirectly.
> 
> Fixes: f94b9707a1c9 ("drm/imx: parallel-display: switch to imx_legacy_bridge / drm_bridge_connector")
> Signed-off-by: Arnd Bergmann <arnd at arndb.de>

I think a correct fix is to select DRM_DISPLAY_HELPER instead.

> ---
>  drivers/gpu/drm/display/Kconfig | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/display/Kconfig b/drivers/gpu/drm/display/Kconfig
> index 0f07cf1483ff..beb05d9bab50 100644
> --- a/drivers/gpu/drm/display/Kconfig
> +++ b/drivers/gpu/drm/display/Kconfig
> @@ -11,14 +11,15 @@ config DRM_DISPLAY_HELPER
>  	help
>  	  DRM helpers for display adapters.
>  
> -if DRM_DISPLAY_HELPER
> -
>  config DRM_BRIDGE_CONNECTOR
>  	bool
>  	select DRM_DISPLAY_HDMI_STATE_HELPER
> +	select DRM_DISPLAY_HELPER
>  	help
>  	  DRM connector implementation terminating DRM bridge chains.
>  
> +if DRM_DISPLAY_HELPER
> +
>  config DRM_DISPLAY_DP_AUX_CEC
>  	bool "Enable DisplayPort CEC-Tunneling-over-AUX HDMI support"
>  	select DRM_DISPLAY_DP_HELPER
> -- 
> 2.39.5
> 

-- 
With best wishes
Dmitry