Re: [REPOST PATCH 3/3] USB: dwc2: Don't turn off the usbphy in suspend if wakeup is enabled

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, 8 Jul 2015, Julius Werner wrote:

> > But I don't see how you will make it work when the root hub itself is
> > not enabled for wakeup and a non-hub device plugged into one of the
> > root hub's ports is enabled.
> >
> > It seems like you would need a usb_hcd_wakeup_not_needed(hcd, port)
> > subroutine.
> 
> We'd just put that in the Tegra platform driver, I guess. Iterate over
> all ports, call usb_wakeup_enabled_descendants() on the connected
> device (if any) and disable that port's PHY if it returns 0 or wasn't
> connected. Since usb_wakeup_enabled_descendants() also counts
> do_remote_wakeup from the device itself and is safe to call even on
> non-hubs, that should work for all cases.

All right, that seems reasonable.  But remember not to do this if 
wakeup is enabled on the root hub -- in that case all the PHYs must 
remain powered because unplugging and plugging are both wakeup events.

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux