Hi, On Fri, Nov 12, 2021 at 8:32 AM Doug Anderson <dianders@xxxxxxxxxx> wrote: > > Hi, > > On Fri, Nov 12, 2021 at 12:43 AM yangcong > <yangcong5@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > > > Through log and waveform, we can see that there will be additional > > suspend/resume when booting. This timing does not meet the ps8640 spec. > > It seems that the delay of 500ms does not satisfied drm_panel_get_modes. > > I increased it to 900ms and it seems that this problem can be solved. > > To be safe, I'd just round up to a full 1000. > > Do be clear: I'm still not convinced that the old 500 ms actually > causes any real problems. I think someone is just measuring with a > scope and upset that they see the device power on and then power off > again. In any case, if we can avoid an extra power cycle at boot then > that seems sane to me. Since this is a tiny change, I'll plan to merge > it some time next week unless someone yells. > > Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx> Pushed to drm-misc-next: aa70a0996b0e drm/bridge: parade-ps8640: Fix additional suspend/resume at bootup