On Tue, 7 Jul 2015, Julius Werner wrote: > > Doug, how would you feel about reworking the patch that exports > > usb_wakeup_enabled_descendants()? Instead of doing it that way, create > > and export a new subroutine in hcd.c called > > usb_hcd_wakeup_not_needed(), or something similar. > > We have a use case with another host controller (Tegra, which I think > is still in the process of being upstreamed) where we are able to > power down PHYs (and thus reduce power consumption) per port. I think > we should prefer the more flexible 'number of wake devices in subtree' > interface to be able to support cases like that. (And for the simple > case, 'if (usb_hcd_wakeup_not_needed(hcd))' and 'if > (!usb_wakeup_enabled_descendants(hcd->self.root_hub))' look pretty > similar anyway.) Okay, that's a good point. 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. 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
