Re: [PATCH] drm/xlnx/zynqmp-dpsub: Fix dependencies for COMPILE_TEST

[Tomi Valkeinen]

Hi,

On 08/04/2026 11:14, Chen-Yu Tsai wrote:
> The zynqmp-dpsub driver does not have build time dependencies on the PHY
> or DMA drivers. These are runtime hardware restrictions.
>
> Group the two dependencies with ARCH_ZYNQMP so that the driver can be
> compile tested without them.
>
> Signed-off-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx>
> ---
> IMO the two driver dependencies could be removed altogether, but that
> would be up to the driver and platform maintainers.
> ---
>   drivers/gpu/drm/xlnx/Kconfig | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/xlnx/Kconfig b/drivers/gpu/drm/xlnx/Kconfig
> index cfabf5e2a0bb..4c6729459f40 100644
> --- a/drivers/gpu/drm/xlnx/Kconfig
> +++ b/drivers/gpu/drm/xlnx/Kconfig
> @@ -1,10 +1,8 @@
>   config DRM_ZYNQMP_DPSUB
>   	tristate "ZynqMP DisplayPort Controller Driver"
> -	depends on ARCH_ZYNQMP || COMPILE_TEST
> +	depends on (ARCH_ZYNQMP && PHY_XILINX_ZYNQMP && XILINX_ZYNQMP_DPDMA) || COMPILE_TEST
>   	depends on COMMON_CLK && DRM && OF
>   	depends on DMADEVICES
> -	depends on PHY_XILINX_ZYNQMP
> -	depends on XILINX_ZYNQMP_DPDMA
>   	select DMA_ENGINE
>   	select DRM_CLIENT_SELECTION
>   	select DRM_DISPLAY_DP_HELPER

I think the above looks more difficult to understand than the current 
version. We should perhaps rather drop the dependencies. But if we go 
that way, then... we can also drop DMADEVICES, DMA_ENGINE, GENERIC_PHY 
at least.

What problem does this solve? Why are these two dependencies bad for 
compile testing, but the other dependencies/selects are ok?

I personally don't mind hard runtime dependencies expressed in the 
Kconfig, as searching for the correct dependency-drivers when your 
driver doesn't probe is always a PITA.

 Tomi