On Thu, Dec 08, 2022 at 11:20:04AM -0800, Douglas Anderson wrote: > Now that we've added the `off-on-delay-us` for the touchpanel > regulator, we can see that we're actually hitting that delay at > bootup. I saw about 200 ms of delay. > > Let's avoid that delay by starting the regulator on. We'll only do > this for eDP devices for the time being. > > NOTE: we _won't_ do this for homestar. Homestar's panel really likes > to be power cycled. It's why the Linux driver for this panel has a > pm_runtime_put_sync_suspend() when the panel is being unprepared but > the normal panel-edp driver doesn't. It's also why this hardware has a > separate power rail for eDP vs. touchscreen, unlike all the other > trogdor boards. We won't start homestar's regulator on. While this > could mean a slight delay on homestar, it is probably a _correct_ > delay. The bootloader might have left the regulator on (it does so in > dev and recovery modes), so if we turned the regulator off at probe > time and we actually hit the delay then we were probably violating T12 > in the panel spec. > > Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx> Reviewed-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
