Re: [PATCH v1] usb: xhci: tegra: Check padctrl interrupt presence in device tree

[Dmitry Osipenko]

21.10.2021 17:57, Dmitry Osipenko пишет:
> It might be wrong to disable device_may_wakeup() because it will change
> the system suspend-resume behaviour, i.e. you won't be able to resume by
> USB event, see [1].
> 
> [1]
> https://elixir.bootlin.com/linux/v5.15-rc6/source/drivers/usb/host/xhci-tegra.c#L1962
> 
> Although, I'm not sure whether this is a correct behaviour to start
> with. Previously, before the offending commit, device_wakeup was never
> enabled for tegra-xusb. Commit message doesn't explain why wakeup is now
> enabled unconditionally, wakeup checks aren't needed at all then. This
> makes no sense, please check it with JC Kuo.

Although, wakeup could be disabled via sysfs, so it makes sense. Still
it's not clear whether it's a correct behaviour to enable wakeup during
system suspend by default. If it wakes machine from suspend when USB
device is plugged/unplugged, then it's a wrong behaviour.