usbnet: handle remote wakeup asap

If usbnet is resumed by remote wakeup, generally there are
some packets comming to be handled, so allocate and submit
rx URBs in usbnet_resume to avoid delays introduced by tasklet.
Otherwise, usbnet may have been runtime suspended before the
usbnet_bh is executed to schedule Rx URBs.

Without the patch, usbnet can't recieve any packets from peer
in runtime suspend state if runtime PM is enabled and
autosuspend_delay is set as zero.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Acked-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 26 insertions, 16 deletions

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 1e46f693eb47..aba769d77459 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1204,6 +1204,21 @@ deferred:
 }
 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
 
+static void rx_alloc_submit(struct usbnet *dev, gfp_t flags)
+{
+        struct urb      *urb;
+        int             i;
+
+        /* don't refill the queue all at once */
+        for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
+                urb = usb_alloc_urb(0, flags);
+                if (urb != NULL) {
+                        if (rx_submit(dev, urb, flags) == -ENOLINK)
+                                return;
+                }
+        }
+}
+
 /*-------------------------------------------------------------------------*/
 
 // tasklet (work deferred from completions, in_irq) or timer
@@ -1243,26 +1258,14 @@ static void usbnet_bh (unsigned long param)
                    !timer_pending (&dev->delay) &&
                    !test_bit (EVENT_RX_HALT, &dev->flags)) {
                 int     temp = dev->rxq.qlen;
-                int     qlen = RX_QLEN (dev);
-
-                if (temp < qlen) {
-                        struct urb      *urb;
-                        int             i;
-
-                        // don't refill the queue all at once
-                        for (i = 0; i < 10 && dev->rxq.qlen < qlen; i++) {
-                                urb = usb_alloc_urb (0, GFP_ATOMIC);
-                                if (urb != NULL) {
-                                        if (rx_submit (dev, urb, GFP_ATOMIC) ==
-                                            -ENOLINK)
-                                                return;
-                                }
-                        }
+
+                if (temp < RX_QLEN(dev)) {
+                        rx_alloc_submit(dev, GFP_ATOMIC);
                         if (temp != dev->rxq.qlen)
                                 netif_dbg(dev, link, dev->net,
                                           "rxqlen %d --> %d\n",
                                           temp, dev->rxq.qlen);
-                        if (dev->rxq.qlen < qlen)
+                        if (dev->rxq.qlen < RX_QLEN(dev))
                                 tasklet_schedule (&dev->bh);
                 }
                 if (dev->txq.qlen < TX_QLEN (dev))
@@ -1572,6 +1575,13 @@ int usbnet_resume (struct usb_interface *intf)
                 spin_unlock_irq(&dev->txq.lock);
 
                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
+                        /* handle remote wakeup ASAP */
+                        if (!dev->wait &&
+                                netif_device_present(dev->net) &&
+                                !timer_pending(&dev->delay) &&
+                                !test_bit(EVENT_RX_HALT, &dev->flags))
+                                        rx_alloc_submit(dev, GFP_KERNEL);
+
                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
                                 netif_tx_wake_all_queues(dev->net);
                         tasklet_schedule (&dev->bh);