Re: [PATCH 10/45] drm/msm/dp: move the pixel clock control to its own API

[Dmitry Baryshkov]

On Thu, Dec 05, 2024 at 08:31:41PM -0800, Abhinav Kumar wrote:
> Enable/Disable of DP pixel clock happens in multiple code paths
> leading to code duplication. Move it into individual helpers so that
> the helpers can be called wherever necessary.
> 
> Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> ---
>  drivers/gpu/drm/msm/dp/dp_ctrl.c | 76 ++++++++++++++++++++++------------------
>  1 file changed, 41 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> index 0bed85b5c8e8133ffa8c74d5de22668905396d09..118f5ed83e464f9f27f813eb39624f9c3189f5ac 100644
> --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
> +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> @@ -1698,6 +1698,30 @@ static bool msm_dp_ctrl_send_phy_test_pattern(struct msm_dp_ctrl_private *ctrl)
>  	return success;
>  }
>  
> +static int msm_dp_ctrl_stream_clk_on(struct msm_dp_ctrl_private *ctrl, unsigned long pixel_rate)
> +{
> +	int ret;
> +
> +	ret = clk_set_rate(ctrl->pixel_clk, pixel_rate * 1000);
> +	if (ret) {
> +		DRM_ERROR("Failed to set pixel clock rate. ret=%d\n", ret);
> +		return ret;
> +	}
> +
> +	if (ctrl->stream_clks_on) {
> +		drm_dbg_dp(ctrl->drm_dev, "pixel clks already enabled\n");
> +	} else {
> +		ret = clk_prepare_enable(ctrl->pixel_clk);
> +		if (ret) {
> +			DRM_ERROR("Failed to start pixel clocks. ret=%d\n", ret);
> +			return ret;
> +		}
> +		ctrl->stream_clks_on = true;
> +	}
> +
> +	return ret;
> +}
> +
>  static int msm_dp_ctrl_process_phy_test_request(struct msm_dp_ctrl_private *ctrl,
>  						struct msm_dp_panel *msm_dp_panel)
>  {
> @@ -1724,22 +1748,7 @@ static int msm_dp_ctrl_process_phy_test_request(struct msm_dp_ctrl_private *ctrl
>  	}
>  
>  	pixel_rate = msm_dp_panel->msm_dp_mode.drm_mode.clock;
> -	ret = clk_set_rate(ctrl->pixel_clk, pixel_rate * 1000);
> -	if (ret) {
> -		DRM_ERROR("Failed to set pixel clock rate. ret=%d\n", ret);
> -		return ret;
> -	}
> -
> -	if (ctrl->stream_clks_on) {
> -		drm_dbg_dp(ctrl->drm_dev, "pixel clks already enabled\n");
> -	} else {
> -		ret = clk_prepare_enable(ctrl->pixel_clk);
> -		if (ret) {
> -			DRM_ERROR("Failed to start pixel clocks. ret=%d\n", ret);
> -			return ret;
> -		}
> -		ctrl->stream_clks_on = true;
> -	}
> +	ret = msm_dp_ctrl_stream_clk_on(ctrl, pixel_rate);
>  
>  	msm_dp_ctrl_send_phy_test_pattern(ctrl);
>  
> @@ -1999,21 +2008,10 @@ int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl, struct msm_dp_panel *
>  
>  	drm_dbg_dp(ctrl->drm_dev, "pixel_rate=%lu\n", pixel_rate);
>  
> -	ret = clk_set_rate(ctrl->pixel_clk, pixel_rate * 1000);
> +	ret = msm_dp_ctrl_stream_clk_on(ctrl, pixel_rate);
>  	if (ret) {
> -		DRM_ERROR("Failed to set pixel clock rate. ret=%d\n", ret);
> -		goto end;
> -	}
> -
> -	if (ctrl->stream_clks_on) {
> -		drm_dbg_dp(ctrl->drm_dev, "pixel clks already enabled\n");
> -	} else {
> -		ret = clk_prepare_enable(ctrl->pixel_clk);
> -		if (ret) {
> -			DRM_ERROR("Failed to start pixel clocks. ret=%d\n", ret);
> -			goto end;
> -		}
> -		ctrl->stream_clks_on = true;
> +		DRM_ERROR("failed to enable stream pixel clk\n");
> +		return ret;
>  	}
>  
>  	/*
> @@ -2041,10 +2039,21 @@ int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl, struct msm_dp_panel *
>  	drm_dbg_dp(ctrl->drm_dev,
>  		"mainlink %s\n", mainlink_ready ? "READY" : "NOT READY");
>  
> -end:
>  	return ret;
>  }
>  
> +static void msm_dp_ctrl_stream_clk_off(struct msm_dp_ctrl *msm_dp_ctrl)

At least this should come right after msm_dp_ctrl_stream_clk_on().

> +{
> +	struct msm_dp_ctrl_private *ctrl;
> +
> +	ctrl = container_of(msm_dp_ctrl, struct msm_dp_ctrl_private, msm_dp_ctrl);
> +
> +	if (ctrl->stream_clks_on) {
> +		clk_disable_unprepare(ctrl->pixel_clk);
> +		ctrl->stream_clks_on = false;
> +	}
> +}
> +
>  void msm_dp_ctrl_clear_vsc_sdp_pkt(struct msm_dp_ctrl *msm_dp_ctrl, struct msm_dp_panel *dp_panel)
>  {
>  	struct msm_dp_ctrl_private *ctrl;
> @@ -2115,10 +2124,7 @@ void msm_dp_ctrl_off(struct msm_dp_ctrl *msm_dp_ctrl)
>  
>  	msm_dp_catalog_ctrl_reset(ctrl->catalog);
>  
> -	if (ctrl->stream_clks_on) {
> -		clk_disable_unprepare(ctrl->pixel_clk);
> -		ctrl->stream_clks_on = false;
> -	}
> +	msm_dp_ctrl_stream_clk_off(msm_dp_ctrl);
>  
>  	dev_pm_opp_set_rate(ctrl->dev, 0);
>  	msm_dp_ctrl_link_clk_disable(&ctrl->msm_dp_ctrl);
> 
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry