USB: EHCI: improve use of per-port status-change bits

This patch (as1634) simplifies some of the code associated with the
per-port change bits added in EHCI-1.1, and in particular it fixes a
bug in the logic of ehci_hub_status_data().  Even if the change bit
doesn't indicate anything happened on a particular port, we still have
to notify the core about changes to the suspend or reset status.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 4d3b294..576b735 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -590,7 +590,7 @@
 	u32		mask;
 	int		ports, i, retval = 1;
 	unsigned long	flags;
-	u32		ppcd = 0;
+	u32		ppcd = ~0;
 
 	/* init status to no-changes */
 	buf [0] = 0;
@@ -628,9 +628,10 @@
 
 	for (i = 0; i < ports; i++) {
 		/* leverage per-port change bits feature */
-		if (ehci->has_ppcd && !(ppcd & (1 << i)))
-			continue;
-		temp = ehci_readl(ehci, &ehci->regs->port_status [i]);
+		if (ppcd & (1 << i))
+			temp = ehci_readl(ehci, &ehci->regs->port_status[i]);
+		else
+			temp = 0;
 
 		/*
 		 * Return status information even for ports with OWNER set.