USB: Avoid 20ms delay in EHCI resume

For function ehci_bus_resume()
- Added flag resume_needed
  No need to wait for 20ms if no port was suspended

- Change mdelay to msleep

- release and reacquire the spinlock around mdelay
Signed-off-by: Nvikram pandita <vikram.pandita@ti.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/ehci-hub.c

@@ -194,6 +194,7 @@ static int ehci_bus_resume (struct usb_hcd *hcd)
 	u32			temp;
 	u32			power_okay;
 	int			i;
+	u8			resume_needed = 0;
 
 	if (time_before (jiffies, ehci->next_statechange))
 		msleep(5);
@@ -228,7 +229,9 @@ static int ehci_bus_resume (struct usb_hcd *hcd)
 
 	/* Some controller/firmware combinations need a delay during which
 	 * they set up the port statuses.  See Bugzilla #8190. */
-	mdelay(8);
+	spin_unlock_irq(&ehci->lock);
+	msleep(8);
+	spin_lock_irq(&ehci->lock);
 
 	/* manually resume the ports we suspended during bus_suspend() */
 	i = HCS_N_PORTS (ehci->hcs_params);
@@ -236,12 +239,21 @@ static int ehci_bus_resume (struct usb_hcd *hcd)
 		temp = ehci_readl(ehci, &ehci->regs->port_status [i]);
 		temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
 		if (test_bit(i, &ehci->bus_suspended) &&
-				(temp & PORT_SUSPEND))
+				(temp & PORT_SUSPEND)) {
 			temp |= PORT_RESUME;
+			resume_needed = 1;
+		}
 		ehci_writel(ehci, temp, &ehci->regs->port_status [i]);
 	}
+
+	/* msleep for 20ms only if code is trying to resume port */
+	if (resume_needed) {
+		spin_unlock_irq(&ehci->lock);
+		msleep(20);
+		spin_lock_irq(&ehci->lock);
+	}
+
 	i = HCS_N_PORTS (ehci->hcs_params);
-	mdelay (20);
 	while (i--) {
 		temp = ehci_readl(ehci, &ehci->regs->port_status [i]);
 		if (test_bit(i, &ehci->bus_suspended) &&