Re: [PATCH v4 08/39] drm/msm/dp: allow dp_ctrl stream APIs to use any panel passed to it

[Dmitry Baryshkov]

On Fri, Apr 10, 2026 at 05:33:43PM +0800, Yongxing Mou wrote:
> From: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> 
> Currently, the dp_ctrl stream APIs operate on their own dp_panel
> which is stored inside the dp_ctrl's private struct. However with MST,
> the stored panel represents the fixed link and not the sinks which
> are hotplugged. Allow the stream related APIs to work on the panel
> which is passed to them rather than the stored one. For SST cases,
> this shall continue to use the stored dp_panel.

Hmm. Why? Can't we get rid of it (in the followup patch)?

> 
> Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> Signed-off-by: Yongxing Mou <yongxing.mou@xxxxxxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/msm/dp/dp_ctrl.c    | 21 +++++++++++----------
>  drivers/gpu/drm/msm/dp/dp_ctrl.h    |  2 +-
>  drivers/gpu/drm/msm/dp/dp_display.c |  2 +-
>  3 files changed, 13 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> index cd58968d4e14..d0eed8c7df45 100644
> --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
> +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> @@ -477,13 +477,14 @@ static void msm_dp_ctrl_config_misc1_misc0(struct msm_dp_ctrl_private *ctrl,
>  	msm_dp_write_link(ctrl, REG_DP_MISC1_MISC0, misc_val);
>  }
>  
> -static void msm_dp_ctrl_configure_source_params(struct msm_dp_ctrl_private *ctrl)
> +static void msm_dp_ctrl_configure_source_params(struct msm_dp_ctrl_private *ctrl,
> +						struct msm_dp_panel *msm_dp_panel)
>  {
> -	msm_dp_ctrl_config_ctrl_streams(ctrl, ctrl->panel);
> +	msm_dp_ctrl_config_ctrl_streams(ctrl, msm_dp_panel);
>  
> -	msm_dp_ctrl_config_misc1_misc0(ctrl, ctrl->panel);
> +	msm_dp_ctrl_config_misc1_misc0(ctrl, msm_dp_panel);
>  
> -	msm_dp_panel_timing_cfg(ctrl->panel, ctrl->msm_dp_ctrl.wide_bus_en);
> +	msm_dp_panel_timing_cfg(msm_dp_panel, ctrl->msm_dp_ctrl.wide_bus_en);
>  }
>  
>  /*
> @@ -2523,7 +2524,7 @@ int msm_dp_ctrl_prepare_stream_on(struct msm_dp_ctrl *msm_dp_ctrl, bool force_li
>  	return ret;
>  }
>  
> -int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl)
> +int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl, struct msm_dp_panel *msm_dp_panel)
>  {
>  	int ret = 0;
>  	bool mainlink_ready = false;
> @@ -2536,10 +2537,10 @@ int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl)
>  
>  	ctrl = container_of(msm_dp_ctrl, struct msm_dp_ctrl_private, msm_dp_ctrl);
>  
> -	pixel_rate_orig = ctrl->panel->msm_dp_mode.drm_mode.clock;
> +	pixel_rate_orig = msm_dp_panel->msm_dp_mode.drm_mode.clock;
>  	pixel_rate = pixel_rate_orig;
>  
> -	if (msm_dp_ctrl->wide_bus_en || ctrl->panel->msm_dp_mode.out_fmt_is_yuv_420)
> +	if (msm_dp_ctrl->wide_bus_en || msm_dp_panel->msm_dp_mode.out_fmt_is_yuv_420)
>  		pixel_rate >>= 1;
>  
>  	drm_dbg_dp(ctrl->drm_dev, "pixel_rate=%lu\n", pixel_rate);
> @@ -2571,14 +2572,14 @@ int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl)
>  	msm_dp_setup_peripheral_flush(ctrl);
>  	msm_dp_ctrl_config_ctrl_link(ctrl);
>  
> -	msm_dp_ctrl_configure_source_params(ctrl);
> +	msm_dp_ctrl_configure_source_params(ctrl, msm_dp_panel);
>  
>  	msm_dp_ctrl_config_msa(ctrl,
>  		ctrl->link->link_params.rate,
>  		pixel_rate_orig,
> -		ctrl->panel->msm_dp_mode.out_fmt_is_yuv_420);
> +		msm_dp_panel->msm_dp_mode.out_fmt_is_yuv_420);
>  
> -	msm_dp_panel_clear_dsc_dto(ctrl->panel);
> +	msm_dp_panel_clear_dsc_dto(msm_dp_panel);
>  
>  	msm_dp_ctrl_setup_tr_unit(ctrl);
>  
> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.h b/drivers/gpu/drm/msm/dp/dp_ctrl.h
> index 5d615f50d13b..32196e97cbe9 100644
> --- a/drivers/gpu/drm/msm/dp/dp_ctrl.h
> +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.h
> @@ -17,7 +17,7 @@ struct msm_dp_ctrl {
>  struct phy;
>  
>  int msm_dp_ctrl_on_link(struct msm_dp_ctrl *msm_dp_ctrl);
> -int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl);
> +int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl, struct msm_dp_panel *msm_dp_panel);
>  int msm_dp_ctrl_prepare_stream_on(struct msm_dp_ctrl *msm_dp_ctrl, bool force_link_train);
>  void msm_dp_ctrl_off(struct msm_dp_ctrl *msm_dp_ctrl);
>  void msm_dp_ctrl_push_idle(struct msm_dp_ctrl *msm_dp_ctrl);
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index 58c46d5ab4d8..1bf1335712bc 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -666,7 +666,7 @@ static int msm_dp_display_enable(struct msm_dp_display_private *dp)
>  		return 0;
>  	}
>  
> -	rc = msm_dp_ctrl_on_stream(dp->ctrl);
> +	rc = msm_dp_ctrl_on_stream(dp->ctrl, dp->panel);
>  	if (!rc)
>  		msm_dp_display->power_on = true;
>  
> 
> -- 
> 2.43.0
> 

-- 
With best wishes
Dmitry