[PATCH v3 32/38] drm/msm/dp: propagate MST state changes to dp mst module

[Dmitry Baryshkov]

On Mon, Aug 25, 2025 at 10:16:18PM +0800, Yongxing Mou wrote:
> Introduce APIs to update the MST state change to MST framework when
> device is plugged/unplugged.
> 
> Signed-off-by: Abhinav Kumar <quic_abhinavk at quicinc.com>
> Signed-off-by: Yongxing Mou <yongxing.mou at oss.qualcomm.com>
> ---
>  drivers/gpu/drm/msm/dp/dp_display.c | 10 +++++++++-
>  drivers/gpu/drm/msm/dp/dp_mst_drm.c | 15 +++++++++++++++
>  drivers/gpu/drm/msm/dp/dp_mst_drm.h |  1 +
>  3 files changed, 25 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index 59720e1ad4b1193e33a4fc6aad0c401eaf9cbec8..909c84a5c97f56138d0d62c5d856d2fd18d36b8c 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -28,6 +28,7 @@
>  #include "dp_drm.h"
>  #include "dp_audio.h"
>  #include "dp_debug.h"
> +#include "dp_mst_drm.h"
>  
>  static bool psr_enabled = false;
>  module_param(psr_enabled, bool, 0);
> @@ -269,7 +270,6 @@ static int msm_dp_display_send_hpd_notification(struct msm_dp_display_private *d
>  		dp->panel->video_test = false;
>  	}
>  
> -

Unrelated

>  	drm_dbg_dp(dp->drm_dev, "type=%d hpd=%d\n",
>  			dp->msm_dp_display.connector_type, hpd);
>  
> @@ -386,6 +386,9 @@ static int msm_dp_display_process_hpd_high(struct msm_dp_display_private *dp)
>  
>  	msm_dp_link_reset_phy_params_vx_px(dp->link);
>  
> +	if (dp->msm_dp_display.mst_active)
> +		msm_dp_mst_display_set_mgr_state(&dp->msm_dp_display, true);

I'd say, this should be a part of the previous patch.

> +
>  	if (!dp->msm_dp_display.internal_hpd)
>  		msm_dp_display_send_hpd_notification(dp, true);
>  
> @@ -608,6 +611,11 @@ static int msm_dp_hpd_unplug_handle(struct msm_dp_display_private *dp, u32 data)
>  	if (!dp->msm_dp_display.internal_hpd)
>  		msm_dp_display_send_hpd_notification(dp, false);
>  
> +	if (dp->msm_dp_display.mst_active) {
> +		msm_dp_mst_display_set_mgr_state(&dp->msm_dp_display, false);
> +		dp->msm_dp_display.mst_active = false;
> +	}
> +
>  	/* signal the disconnect event early to ensure proper teardown */
>  	msm_dp_display_handle_plugged_change(&dp->msm_dp_display, false);
>  
> diff --git a/drivers/gpu/drm/msm/dp/dp_mst_drm.c b/drivers/gpu/drm/msm/dp/dp_mst_drm.c
> index 331d08854049d9c74d49aa231f3507539986099e..ca654b1963467c8220dd7ee073f25216455d0490 100644
> --- a/drivers/gpu/drm/msm/dp/dp_mst_drm.c
> +++ b/drivers/gpu/drm/msm/dp/dp_mst_drm.c
> @@ -924,6 +924,21 @@ msm_dp_mst_add_connector(struct drm_dp_mst_topology_mgr *mgr,
>  	return connector;
>  }
>  
> +int msm_dp_mst_display_set_mgr_state(struct msm_dp *dp_display, bool state)
> +{
> +	int rc;
> +	struct msm_dp_mst *mst = dp_display->msm_dp_mst;

Reverse X-mas

> +
> +	rc = drm_dp_mst_topology_mgr_set_mst(&mst->mst_mgr, state);
> +	if (rc < 0) {
> +		DRM_ERROR("failed to set topology mgr state to %d. rc %d\n",
> +			  state, rc);
> +	}
> +
> +	drm_dbg_dp(dp_display->drm_dev, "dp_mst_display_set_mgr_state state:%d\n", state);
> +	return rc;
> +}
> +
>  static const struct drm_dp_mst_topology_cbs msm_dp_mst_drm_cbs = {
>  	.add_connector = msm_dp_mst_add_connector,
>  };
> diff --git a/drivers/gpu/drm/msm/dp/dp_mst_drm.h b/drivers/gpu/drm/msm/dp/dp_mst_drm.h
> index 5e1b4db8aea4506b0e1cc1cc68980dd617d3f72a..8fe6cbbe741da4abb232256b3a15ba6b16ca4f3e 100644
> --- a/drivers/gpu/drm/msm/dp/dp_mst_drm.h
> +++ b/drivers/gpu/drm/msm/dp/dp_mst_drm.h
> @@ -87,5 +87,6 @@ int msm_dp_mst_drm_bridge_init(struct msm_dp *dp, struct drm_encoder *encoder);
>  int msm_dp_mst_init(struct msm_dp *dp_display, u32 max_streams, struct drm_dp_aux *drm_aux);
>  
>  void msm_dp_mst_display_hpd_irq(struct msm_dp *dp_display);
> +int msm_dp_mst_display_set_mgr_state(struct msm_dp *dp_display, bool state);
>  
>  #endif /* _DP_MST_DRM_H_ */
> 
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry