USB: EHCI: fix remote-wakeup regression

This patch (as1097) fixes a bug in the remote-wakeup handling in
ehci-hcd.  The driver currently does not keep track of whether the
change-suspend feature is enabled for each port; the feature is
automatically reset the first time it is read.  But recent changes to
the hub driver require that the feature be read at least twice in
order to work properly.

A bit-vector is added for storing the change-suspend feature values.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/ehci-hub.c

@@ -609,7 +609,7 @@ static int ehci_hub_control (
 			}
 			break;
 		case USB_PORT_FEAT_C_SUSPEND:
-			/* we auto-clear this feature */
+			clear_bit(wIndex, &ehci->port_c_suspend);
 			break;
 		case USB_PORT_FEAT_POWER:
 			if (HCS_PPC (ehci->hcs_params))
@@ -688,7 +688,7 @@ static int ehci_hub_control (
 			/* resume completed? */
 			else if (time_after_eq(jiffies,
 					ehci->reset_done[wIndex])) {
-				status |= 1 << USB_PORT_FEAT_C_SUSPEND;
+				set_bit(wIndex, &ehci->port_c_suspend);
 				ehci->reset_done[wIndex] = 0;
 
 				/* stop resume signaling */
@@ -765,6 +765,8 @@ static int ehci_hub_control (
 			status |= 1 << USB_PORT_FEAT_RESET;
 		if (temp & PORT_POWER)
 			status |= 1 << USB_PORT_FEAT_POWER;
+		if (test_bit(wIndex, &ehci->port_c_suspend))
+			status |= 1 << USB_PORT_FEAT_C_SUSPEND;
 
 #ifndef	VERBOSE_DEBUG
 	if (status & ~0xffff)	/* only if wPortChange is interesting */

drivers/usb/host/ehci.h

@@ -97,6 +97,8 @@ struct ehci_hcd {			/* one per controller */
 			dedicated to the companion controller */
 	unsigned long		owned_ports;		/* which ports are
 			owned by the companion during a bus suspend */
+	unsigned long		port_c_suspend;		/* which ports have
+			the change-suspend feature turned on */
 
 	/* per-HC memory pools (could be per-bus, but ...) */
 	struct dma_pool		*qh_pool;	/* qh per active urb */