Quoting khsieh@xxxxxxxxxxxxxx (2021-08-04 08:48:04) > On 2021-08-03 12:05, Stephen Boyd wrote: > > Quoting Kuogee Hsieh (2021-08-03 09:25:13) > >> @@ -1327,14 +1327,26 @@ static int dp_pm_resume(struct device *dev) > >> > >> dp_catalog_ctrl_hpd_config(dp->catalog); > >> > >> - status = dp_catalog_link_is_connected(dp->catalog); > >> + /* > >> + * set sink to normal operation mode -- D0 > >> + * before dpcd read > >> + */ > >> + dp_link_psm_config(dp->link, &dp->panel->link_info, false); > >> + > >> + /* if sink conencted, do dpcd read sink count */ > > > > s/conencted/connected/ > > > > This also just says what the code is doing. Why do we only read the > > sink > > count if the link is connected? Can we read the sink count even if the > > link isn't connected and then consider sink count as 0 if trying to > > read > > fails? > > > yes, we can do that. > But it will suffer aux time out and retry. > i think it is better to avoid this overhead by check connection first. > Hmm ok. Maybe something is wrong with the aux channel where it doesn't avoid the timeout if the connection is obviously not established yet.