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USB: EHCI: carry out port handover during each root-hub resume

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This patch (as1044) causes EHCI port handover for non-high-speed
devices to occur during every root-hub resume, not just in cases where
the controller lost power or was reset.  This is necessary because:

	When some machines go into suspend, they remove power from
	on-board USB devices while retaining suspend current for USB
	controllers.

	The user might well unplug a USB device while the system is
	suspended and then plug it back in before resuming.

A corresponding change is made to the core resume routine; now
high-speed root hubs will always be resumed when the system wakes up,
even if they were suspended before the system went to sleep.  If this
weren't done then EHCI port handover wouldn't work, since it is called
when the EHCI root hub is resumed.

Finally, a comment is added to the hub driver explaining the khubd has
to be freezable; if it weren't frozen then it could interfere with
port handover.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern
2008-03-03 15:15:36 -05:00
committed by Greg Kroah-Hartman
parent 8f7f85e9f9
commit 3bb1af5243
4 changed files with 14 additions and 6 deletions
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4
drivers/usb/host/ehci-hub.c
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@ -281,9 +281,7 @@ static int ehci_bus_resume (struct usb_hcd *hcd)
ehci_writel(ehci, INTR_MASK, &ehci->regs->intr_enable);
spin_unlock_irq (&ehci->lock);
if (!power_okay)
ehci_handover_companion_ports(ehci);
ehci_handover_companion_ports(ehci);
return 0;
}