can: ems_usb: Fix possible tx overflow

[pandora-kernel.git] / drivers / net / can / usb / ems_usb.c

diff --git a/drivers/net/can/usb/ems_usb.c b/drivers/net/can/usb/ems_usb.c
index a72c7bf..3b8c4da 100644 (file)
--- a/drivers/net/can/usb/ems_usb.c
+++ b/drivers/net/can/usb/ems_usb.c
@@ -118,6 +118,9 @@ MODULE_LICENSE("GPL v2");
  */
 #define EMS_USB_ARM7_CLOCK 8000000
 
+#define CPC_TX_QUEUE_TRIGGER_LOW       25
+#define CPC_TX_QUEUE_TRIGGER_HIGH      35
+
 /*
  * CAN-Message representation in a CPC_MSG. Message object type is
  * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
@@ -280,6 +283,11 @@ static void ems_usb_read_interrupt_callback(struct urb *urb)
        switch (urb->status) {
        case 0:
                dev->free_slots = dev->intr_in_buffer[1];
+               if(dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH){
+                       if (netif_queue_stopped(netdev)){
+                               netif_wake_queue(netdev);
+                       }
+               }
                break;
 
        case -ECONNRESET: /* unlink */
@@ -535,8 +543,6 @@ static void ems_usb_write_bulk_callback(struct urb *urb)
        /* Release context */
        context->echo_index = MAX_TX_URBS;
 
-       if (netif_queue_stopped(netdev))
-               netif_wake_queue(netdev);
 }
 
 /*
@@ -596,7 +602,7 @@ static int ems_usb_start(struct ems_usb *dev)
        int err, i;
 
        dev->intr_in_buffer[0] = 0;
-       dev->free_slots = 15; /* initial size */
+       dev->free_slots = 50; /* initial size */
 
        for (i = 0; i < MAX_RX_URBS; i++) {
                struct urb *urb = NULL;
@@ -858,7 +864,7 @@ static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *ne
 
                /* Slow down tx path */
                if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
-                   dev->free_slots < 5) {
+                   dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
                        netif_stop_queue(netdev);
                }
        }