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

Yongxing Mou yongxing.mou at oss.qualcomm.com
Mon Aug 17 01:01:34 PDT 2026



On 7/12/2026 6:56 PM, Dmitry Baryshkov wrote:
> 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.
> 
Got it .
>> +	}
>>   
>>   	msm_dp_link_reset_phy_params_vx_px(dp->link);
>>   
>>
>> -- 
>> 2.43.0
>>
> 




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