Quoting Kuogee Hsieh (2021-08-05 13:44:55) > Initialize both pre-emphasis and voltage swing level to 0 before > start link training and do not end link training until video is > ready to reduce the period between end of link training and video > start to meet Link Layer CTS requirement. Some dongle main link > symbol may become unlocked again if host did not end link training > soon enough after completion of link training 2. Host have to re > train main link if loss of symbol locked detected before end link > training so that the coming video stream can be transmitted to sink > properly. This fixes Link Layer CTS cases 4.3.2.1, 4.3.2.2, 4.3.2.3 > and 4.3.2.4. > > Changes in v3: > -- merge retrain link if loss of symbol locked happen into this patch > -- replace dp_ctrl_loss_symbol_lock() with dp_ctrl_channel_eq_ok() > > Signed-off-by: Kuogee Hsieh <khsieh@xxxxxxxxxxxxxx> > --- Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>