Re: [PATCH v4 39/39] drm/msm/dp: Add MST stream support for supported DP controllers

[Konrad Dybcio]

On 4/10/26 11:34 AM, Yongxing Mou wrote:
> Enables MST support for MSM DP controllers that support it, allowing each
> controller to handle up to two or four DisplayPort streams. All necessary
> MST support code was already implemented in the previous series of patches.
> 
> Signed-off-by: Yongxing Mou <yongxing.mou@xxxxxxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/msm/dp/dp_display.c | 42 ++++++++++++++++++++++++-------------
>  1 file changed, 28 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index ca89e20b7563..f632b4f64ccc 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -107,16 +107,21 @@ struct msm_dp_desc {
>  };
>  
>  static const struct msm_dp_desc msm_dp_desc_glymur[] = {
> -	{ .io_start = 0x0af54000, .id = MSM_DP_CONTROLLER_0, .wide_bus_supported = true },

Please reformat all the changes so that the entries have one assignment a line

> -	{ .io_start = 0x0af5c000, .id = MSM_DP_CONTROLLER_1, .wide_bus_supported = true },
> -	{ .io_start = 0x0af64000, .id = MSM_DP_CONTROLLER_2, .wide_bus_supported = true },
> +	{ .io_start = 0x0af54000, .id = MSM_DP_CONTROLLER_0, .wide_bus_supported = true,
> +	  .mst_streams = 2 },
> +	{ .io_start = 0x0af5c000, .id = MSM_DP_CONTROLLER_1, .wide_bus_supported = true,
> +	  .mst_streams = 2 },
> +	{ .io_start = 0x0af64000, .id = MSM_DP_CONTROLLER_2, .wide_bus_supported = true,
> +	  .mst_streams = 2 },
>  	{ .io_start = 0x0af6c000, .id = MSM_DP_CONTROLLER_3, .wide_bus_supported = true },
>  	{}

All 4 DPTXes on Glymur have the address spaces that suggest 4-way MST


>  };
>  
>  static const struct msm_dp_desc msm_dp_desc_sa8775p[] = {
> -	{ .io_start = 0x0af54000, .id = MSM_DP_CONTROLLER_0, .wide_bus_supported = true },
> -	{ .io_start = 0x0af5c000, .id = MSM_DP_CONTROLLER_1, .wide_bus_supported = true },
> +	{ .io_start = 0x0af54000, .id = MSM_DP_CONTROLLER_0, .wide_bus_supported = true,
> +	  .mst_streams = 4},
> +	{ .io_start = 0x0af5c000, .id = MSM_DP_CONTROLLER_1, .wide_bus_supported = true,
> +	  .mst_streams = 2},
>  	{ .io_start = 0x22154000, .id = MSM_DP_CONTROLLER_0, .wide_bus_supported = true },
>  	{ .io_start = 0x2215c000, .id = MSM_DP_CONTROLLER_1, .wide_bus_supported = true },
>  	{}

Same thing here

> @@ -133,38 +138,47 @@ static const struct msm_dp_desc msm_dp_desc_sc7180[] = {
>  };
>  
>  static const struct msm_dp_desc msm_dp_desc_sc7280[] = {
> -	{ .io_start = 0x0ae90000, .id = MSM_DP_CONTROLLER_0, .wide_bus_supported = true },
> +	{ .io_start = 0x0ae90000, .id = MSM_DP_CONTROLLER_0, .wide_bus_supported = true,
> +	  .mst_streams = 2 },
>  	{ .io_start = 0x0aea0000, .id = MSM_DP_CONTROLLER_1, .wide_bus_supported = true },
>  	{}

Interestingly the eDP host on 7280 also has the registers for MST..

Please recheck all the entries

Konrad