Re: [PATCH RESEND v5 11/25] drm/msm/dp: move link-level teardown from display_disable to display_unprepare

[Yongxing Mou <yongxing.mou@oss.qualcomm.com>]

On 7/13/2026 2:20 AM, Dmitry Baryshkov wrote:
> On Mon, Jun 29, 2026 at 10:14:32PM +0800, Yongxing Mou wrote:
>> From: Abhinav Kumar <quic_abhinavk@quicinc.com>
>>
>> msm_dp_display_disable() currently mixes stream-level shutdown
>> (disable VSC SDP, off pixel clk, clear power_on) with link-level
>> teardown (PSM config when sink_count==0, off_link, PHY re-init or
>> host PHY exit).
>>
>> For DP MST the same link is shared across multiple streams, so
>> disabling one stream must not tear down the link. Move the
>> link-level steps into msm_dp_display_unprepare() so that
>> display_disable() handles only the per-stream sequence, mirroring
>> the split already present on the prepare path
>> (display_prepare_link vs display_set_mode / display_enable).
>>
>> SST behaviour is unchanged: atomic_post_disable() still calls
>> display_disable() followed by display_unprepare() in the same
>> order, and the cached dp->panel used inside unprepare is the same
>> panel that was previously passed in.
>>
>> Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
>> Signed-off-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com>
>> ---
>>   drivers/gpu/drm/msm/dp/dp_display.c | 24 ++++++++++++------------
>>   1 file changed, 12 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
>> index 1af56c84b82e..1680a67284a7 100644
>> --- a/drivers/gpu/drm/msm/dp/dp_display.c
>> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
>> @@ -731,18 +731,6 @@ static int msm_dp_display_disable(struct msm_dp_display_private *dp,
>>   
>>   	msm_dp_ctrl_off_pixel_clk(dp->ctrl, msm_dp_panel->stream_id);
>>   
>> -	/* dongle is still connected but sinks are disconnected */
>> -	if (dp->link->sink_count == 0)
>> -		msm_dp_link_psm_config(dp->link, &msm_dp_panel->link_info, true);
>> -
>> -	msm_dp_ctrl_off_link(dp->ctrl, dp->panel);
>> -
>> -	if (dp->link->sink_count == 0)
>> -		/* re-init the PHY so that we can listen to Dongle disconnect */
>> -		msm_dp_ctrl_reinit_phy(dp->ctrl);
>> -	else
>> -		msm_dp_display_host_phy_exit(dp);
>> -
>>   	msm_dp_display->power_on = false;
> 
> The list is no longer powred on at this point. So, this is wrong.
> 
Got it, here should also move to msm_dp_display_unprepare().
>>   
>>   	drm_dbg_dp(dp->drm_dev, "sink count: %d\n", dp->link->sink_count);
>> @@ -1533,6 +1521,18 @@ static void msm_dp_display_unprepare(struct msm_dp_display_private *dp)
>>   {
>>   	struct msm_dp *msm_dp_display = &dp->msm_dp_display;
>>   
>> +	/* dongle is still connected but sinks are disconnected */
>> +	if (dp->link->sink_count == 0)
>> +		msm_dp_link_psm_config(dp->link, &dp->panel->link_info, true);
>> +
>> +	msm_dp_ctrl_off_link(dp->ctrl, dp->panel);
>> +
>> +	if (dp->link->sink_count == 0)
>> +		/* re-init the PHY so that we can listen to Dongle disconnect */
>> +		msm_dp_ctrl_reinit_phy(dp->ctrl);
>> +	else
>> +		msm_dp_display_host_phy_exit(dp);
>> +
>>   	pm_runtime_put_sync(&msm_dp_display->pdev->dev);
>>   
>>   	drm_dbg_dp(dp->drm_dev, "type=%d Done\n", msm_dp_display->connector_type);
>>
>> -- 
>> 2.43.0
>>
>