Re: [PATCH v3 4/8] drm/msm/dpu: use single CTL if it is the only CTL returned by RM

[Jessica Zhang <quic_jesszhan@quicinc.com>]

On 3/6/2025 10:24 PM, Dmitry Baryshkov wrote:
> From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> 
> On DPU >= 5.0 CTL blocks were reworked in order to support using a
> single CTL for all outputs. In preparation of reworking the RM code to
> return single CTL make sure that dpu_encoder can cope with that.
> 
> Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
> Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Reviewed-by: Jessica Zhang <quic_jesszhan@quicinc.com>

> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> index 0eed93a4d056beda6b54c0d20f027a53c84f67db..b5e8ba592d8af298a52924d34a573d4f9e05c476 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> @@ -1247,7 +1247,11 @@ static void dpu_encoder_virt_atomic_mode_set(struct drm_encoder *drm_enc,
>   			return;
>   		}
>   
> -		phys->hw_ctl = i < num_ctl ? to_dpu_hw_ctl(hw_ctl[i]) : NULL;
> +		/* Use first (and only) CTL if active CTLs are supported */
> +		if (num_ctl == 1)
> +			phys->hw_ctl = to_dpu_hw_ctl(hw_ctl[0]);
> +		else
> +			phys->hw_ctl = i < num_ctl ? to_dpu_hw_ctl(hw_ctl[i]) : NULL;
>   		if (!phys->hw_ctl) {
>   			DPU_ERROR_ENC(dpu_enc,
>   				"no ctl block assigned at idx: %d\n", i);
>