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SubjectRe: [PATCH v11 1/4] drm/msm/dp: do not initialize phy until plugin interrupt received
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On 1/13/2022 11:47 AM, Stephen Boyd wrote:
> Quoting Kuogee Hsieh (2022-01-13 09:51:42)
>> On 1/12/2022 8:13 PM, Stephen Boyd wrote:
>>>>>> - if (dp->usbpd->orientation == ORIENTATION_CC2)
>>>>>> - flip = true;
>>>>>> + dp_power_init(dp->power, false);
>>>>>> + dp_ctrl_reset_irq_ctrl(dp->ctrl, true);
>>>>>> +
>>>>>> + /*
>>>>>> + * eDP is the embedded primary display and has its own phy
>>>>>> + * initialize phy immediately
>>>>> Question still stands why we can't wait for hpd high from the eDP panel.
>>>>> Also, I think "has its own phy" means that it's not part of a combo
>>>>> USB+DP phy? Can you please clarify?
Correct, eDP has its dedicated phy which is not part of combo phy.
>>>>>> + */
>>>>>> + if (dp->dp_display.connector_type == DRM_MODE_CONNECTOR_eDP)
>>>>>> + dp_display_host_phy_init(dp);
>>>>>>
>>>>>> - dp_power_init(dp->power, flip);
>>>>>> - dp_ctrl_host_init(dp->ctrl, flip, reset);
>>>>>> dp_aux_init(dp->aux);
>>>>>> dp->core_initialized = true;
>>>>>> }
>>>>>> @@ -1306,20 +1330,23 @@ static int dp_pm_resume(struct device *dev)
>>>>>> dp->hpd_state = ST_DISCONNECTED;
>>>>>>
>>>>>> /* turn on dp ctrl/phy */
>>>>>> - dp_display_host_init(dp, true);
>>>>>> + dp_display_host_init(dp);
>>>>>>
>>>>>> dp_catalog_ctrl_hpd_config(dp->catalog);
>>>>>>
>>>>>> - /*
>>>>>> - * set sink to normal operation mode -- D0
>>>>>> - * before dpcd read
>>>>>> - */
>>>>>> - dp_link_psm_config(dp->link, &dp->panel->link_info, false);
>>>>>>
>>>>>> if (dp_catalog_link_is_connected(dp->catalog)) {
>>>>>> + /*
>>>>>> + * set sink to normal operation mode -- D0
>>>>>> + * before dpcd read
>>>>>> + */
>>>>>> + dp_display_host_phy_init(dp);
>>>>>> + dp_link_psm_config(dp->link, &dp->panel->link_info, false);
>>>>>> sink_count = drm_dp_read_sink_count(dp->aux);
>>>>>> if (sink_count < 0)
>>>>>> sink_count = 0;
>>>>>> +
>>>>>> + dp_display_host_phy_exit(dp);
>>>>> Why is the phy exited on resume when the link is still connected? Is
>>>>> this supposed to be done only when the sink_count is 0? And how does
>>>>> this interact with eDP where the phy is initialized by the call to
>>>>> dp_display_host_init() earlier in this function.

At beginning of dp_pm_resume bot core_initialized and phy_initialized
should be off.

However at the case of dongle still connected to DUT, we have to read
dongle dpcd to decided any hdmi connect to dongle (sink_count != 0). in
this case, we have to turn on phy to perform dpcd read and  turn off phy
after read so the following plugged-in interrupt can be handled correctly.

>>>>>> }
>>>>>>
>>>>>> dp->link->sink_count = sink_count;
>>> Any response to the above two comments?
> ??

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