[PATCH v2 02/12] drm/i915/dp_mst: Simplify handling the single-bpp case during state computation

[Luca Coelho]

On Mon, 2025-04-28 at 16:31 +0300, Imre Deak wrote:
> A follow-up change wants to skip invalid bpps in the bpp select loop of
> a stream state computation. To allow for that, using the usual
> 'continue' statement in the loop, change the way the sinlge-bpp range is
> handled.
> 
> Cc: Jani Nikula <jani.nikula at intel.com>
> Signed-off-by: Imre Deak <imre.deak at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp_mst.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 49b836cd8816c..d8033e55dc093 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -283,6 +283,12 @@ int intel_dp_mtp_tu_compute_config(struct intel_dp *intel_dp,
>  					   fxp_q4_to_frac(max_bpp_x16) ||
>  					   fxp_q4_to_frac(bpp_step_x16)));
>  
> +	if (!bpp_step_x16) {
> +		/* Allow using zero step only to indicate single try for a given bpp. */
> +		drm_WARN_ON(display->drm, min_bpp_x16 != max_bpp_x16);
> +		bpp_step_x16 = 1;
> +	}
> +
>  	if (is_mst) {
>  		mst_state = drm_atomic_get_mst_topology_state(state, &intel_dp->mst.mgr);
>  		if (IS_ERR(mst_state))
> @@ -408,10 +414,6 @@ int intel_dp_mtp_tu_compute_config(struct intel_dp *intel_dp,
>  
>  			break;
>  		}
> -
> -		/* Allow using zero step to indicate one try */
> -		if (!bpp_step_x16)
> -			break;
>  	}
>  
>  	if (slots < 0) {

Looks good.

Reviewed-by: Luca Coelho <luciano.coelho at intel.com>

--
Cheers,
Luca.