Re: [PATCH v3 1/8] drm/msm/dpu: don't overwrite CTL_MERGE_3D_ACTIVE register

[Jessica Zhang <quic_jesszhan@quicinc.com>]

On 3/6/2025 10:24 PM, Dmitry Baryshkov wrote:
> From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> 
> In case of complex pipelines (e.g. the forthcoming quad-pipe) the DPU
> might use more that one MERGE_3D block for a single output.  Follow the
> pattern and extend the CTL_MERGE_3D_ACTIVE active register instead of
> simply writing new value there. Currently at most one MERGE_3D block is
> being used, so this has no impact on existing targets.
> 
> 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_hw_ctl.c | 10 ++++++----
>   1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c
> index 411a7cf088eb72f856940c09b0af9e108ccade4b..cef3bfaa4af82ebc55fb8cf76adef3075c7d73e3 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c
> @@ -563,6 +563,7 @@ static void dpu_hw_ctl_intf_cfg_v1(struct dpu_hw_ctl *ctx,
>   	u32 wb_active = 0;
>   	u32 cwb_active = 0;
>   	u32 mode_sel = 0;
> +	u32 merge_3d_active = 0;
>   
>   	/* CTL_TOP[31:28] carries group_id to collate CTL paths
>   	 * per VM. Explicitly disable it until VM support is
> @@ -578,6 +579,7 @@ static void dpu_hw_ctl_intf_cfg_v1(struct dpu_hw_ctl *ctx,
>   	wb_active = DPU_REG_READ(c, CTL_WB_ACTIVE);
>   	cwb_active = DPU_REG_READ(c, CTL_CWB_ACTIVE);
>   	dsc_active = DPU_REG_READ(c, CTL_DSC_ACTIVE);
> +	merge_3d_active = DPU_REG_READ(c, CTL_MERGE_3D_ACTIVE);
>   
>   	if (cfg->intf)
>   		intf_active |= BIT(cfg->intf - INTF_0);
> @@ -591,15 +593,15 @@ static void dpu_hw_ctl_intf_cfg_v1(struct dpu_hw_ctl *ctx,
>   	if (cfg->dsc)
>   		dsc_active |= cfg->dsc;
>   
> +	if (cfg->merge_3d)
> +		merge_3d_active |= BIT(cfg->merge_3d - MERGE_3D_0);
> +
>   	DPU_REG_WRITE(c, CTL_TOP, mode_sel);
>   	DPU_REG_WRITE(c, CTL_INTF_ACTIVE, intf_active);
>   	DPU_REG_WRITE(c, CTL_WB_ACTIVE, wb_active);
>   	DPU_REG_WRITE(c, CTL_CWB_ACTIVE, cwb_active);
>   	DPU_REG_WRITE(c, CTL_DSC_ACTIVE, dsc_active);
> -
> -	if (cfg->merge_3d)
> -		DPU_REG_WRITE(c, CTL_MERGE_3D_ACTIVE,
> -			      BIT(cfg->merge_3d - MERGE_3D_0));
> +	DPU_REG_WRITE(c, CTL_MERGE_3D_ACTIVE, merge_3d_active);
>   
>   	if (cfg->cdm)
>   		DPU_REG_WRITE(c, CTL_CDM_ACTIVE, cfg->cdm);
>