Re: [PATCH v2 1/2] usb: dwc2: optionally assert phy "full reset" when waking up

From: Rob Herring
Date: Mon Nov 02 2015 - 11:13:03 EST

On Fri, Oct 30, 2015 at 3:17 PM, Douglas Anderson <dianders@xxxxxxxxxxxx> wrote:
> From: Doug Anderson <dianders@xxxxxxxxxxxx>
> On the rk3288 USB host-only port (the one that's not the OTG-enabled
> port) the PHY can get into a bad state when a wakeup is asserted (not
> just a wakeup from full system suspend but also a wakeup from
> autosuspend).

I would think re-enumerating means autosuspend is broken.

> We can get the PHY out of its bad state by asserting its "port reset",
> but unfortunately that seems to assert a reset onto the USB bus so it
> could confuse things if we don't actually deenumerate / reenumerate the
> device.
> We can also get the PHY out of its bad state by fully resetting it using
> the reset from the CRU (clock reset unit), which does a more full
> reset. The CRU-based reset appears to actually cause devices on the bus
> to be removed and reinserted, which fixes the problem (albeit in a hacky
> way).

The reset from the CRU goes to the PHY, correct? Therefore, the
binding should reflect that. Connecting it to the host controller is a

So describe the reset connection properly and then add a .phy_reset()
hook to the phy subsystem. Then call that when flag property you added
is set.

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