On Tue, 31 Dec 2013, Randy Dunlap wrote:
> >>> @@ -3334,7 +3334,7 @@ static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
> >>>
> >>> udev = hub->ports[port1 - 1]->child;
> >>> if (udev && udev->can_submit) {
> >>> - dev_warn(&intf->dev, "port %d nyet suspended\n", port1);
> >
> >> nyet is a special kind of USB protocol token (packet ID).
> >> I suspect that 'nyet' is correct here.
It is; "nyet" is a semi-humorous contraction of "not yet", as Sergei
pointed out.
Changing the string to "port %d not suspended yet\n" would be
acceptable.
> > NYET token doesn't have anything to do with port suspend.
>
> Not that this is in the EHCI driver, but include/linux/usb/ehci_def.h
> seems to think that a port can be suspended due to a NYET (or I am
> misreading it; would not be a surprise):
>
> #define PORTSC_SUSPEND_STS_NYET 1
This is meant for L1 suspend, which was added to the spec in USB 2.1
and EHCI-1.1. The NYET packet indicates that the downstream device did
not enter L1 suspend when requested. However, the dev_warn string
above was written well before the EHCI-1.1 addendum appeared, and in
fact the EHCI driver doesn't support L1 suspend. The string refers to
an ordinary suspend (sometimes referred to as L2 suspend).
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
