PM: USB HCDs use PM_EVENT_PRETHAW

This teaches several USB host controller drivers to treat PRETHAW as a chip
reset since the controller, and all devices connected to it, are no longer in
states compatible with how the snapshotted suspend() left them.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index cadffac..6967ab7 100644
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -238,6 +238,12 @@
 	writel (0, &ehci->regs->intr_enable);
 	(void)readl(&ehci->regs->intr_enable);
 
+	/* make sure snapshot being resumed re-enumerates everything */
+	if (message.event == PM_EVENT_PRETHAW) {
+		ehci_halt(ehci);
+		ehci_reset(ehci);
+	}
+
 	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
  bail:
 	spin_unlock_irqrestore (&ehci->lock, flags);