Quoting Bjorn Andersson (2021-11-05 10:48:37) > On Fri 05 Nov 10:28 PDT 2021, Kuogee Hsieh wrote: > > > From: Kuogee Hsieh <khsieh@xxxxxxxxxxxxxx> > > > > Combo phy supports both USB and DP simultaneously. There may has a > > possible conflict during phy initialization phase between USB and > > DP driver which may cause USB phy timeout when USB tries to power > > up its phy. This patch has the DP driver not initialize its phy > > during DP driver initialization phase. Instead DP driver only enable > > required regulators and clocks so that it is able to receive HPD > > interrupts after completion of initialization phase. DP driver will > > initialize its phy when HPD plug-in interrupt received. > > Is this a hardware requirement, or is this a issue with the current > implementation of the QMP combo phy driver? We should not hack up the DP > driver to circumvent the latter. > > Also, I don't suppose there's anything here that prevents the HPD to > come before the USB PHY is powered up? Even though that seems less > likely in practice... > > > This patch also provides a positive side effects which balance regulator > > enable count since regulator only enabled at initialize phase and resume > > and disabled at followed suspend. > > > > Is this something that needs to be fixed separately, so that it can be > backported to stable kernels? Agreed. Please split the regulator balance problem from the DP initialization delay.
