[PATCH 5/5] drm/msm/dp: mark the SST connector disconnected when MST is enabled

Dmitry Baryshkov dmitry.baryshkov at oss.qualcomm.com
Sun Jul 12 03:56:58 PDT 2026


On Mon, Jun 29, 2026 at 10:48:07PM +0800, Yongxing Mou wrote:
> When MST becomes active, the initial HPD plug notification updates the
> SST connector state to connected.
> 
> However, the subsequent SST connector detect path reports disconnected
> while MST is enabled. This connected -> disconnected transition is then
> observed by the polling logic and may result in an unnecessary hotplug
> event.
> 
> Set the SST connector state to disconnected immediately after MST is
> initialized so that the detect path does not introduce a transient
> state change.
> 
> Signed-off-by: Yongxing Mou <yongxing.mou at oss.qualcomm.com>
> ---
>  drivers/gpu/drm/msm/dp/dp_display.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index 4ee391cc7165..f8ca60d6d714 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -352,8 +352,10 @@ static int msm_dp_display_process_hpd_high(struct msm_dp_display_private *dp)
>  	if (dp->max_stream > 1 && drm_dp_read_mst_cap(dp->aux, dp->panel->dpcd))
>  		msm_dp_display_mst_init(dp);
>  
> -	if (dp->msm_dp_display.mst_active)
> +	if (dp->msm_dp_display.mst_active) {
> +		connector->status = connector_status_disconnected;
>  		msm_dp_mst_display_set_mgr_state(&dp->msm_dp_display, true);

This should be a part of the MST series.

> +	}
>  
>  	msm_dp_link_reset_phy_params_vx_px(dp->link);
>  
> 
> -- 
> 2.43.0
> 

-- 
With best wishes
Dmitry



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