[PATCH] (4/4) acenic - don't spin forever in hard_start_xmit

[Stephen Hemminger <shemminger@xxxxxxxx>]

If driver is stuck due to ring full and hardware or link error, don't spin
forever in the hard_start_xmit routine.

Signed-off-by: Stephen Hemminger <shemminger@xxxxxxxx>

diff -Nru a/drivers/net/acenic.c b/drivers/net/acenic.c
--- a/drivers/net/acenic.c      2004-09-20 10:47:22 -07:00
+++ b/drivers/net/acenic.c      2004-09-20 10:47:22 -07:00
@@ -2499,6 +2499,7 @@
        struct ace_regs __iomem *regs = ap->regs;
        struct tx_desc *desc;
        u32 idx, flagsize;
+       unsigned long maxjiff = jiffies + 3*HZ;
 
 restart:
        idx = ap->tx_prd;
@@ -2602,7 +2603,7 @@
        }
 
        dev->trans_start = jiffies;
-       return 0;
+       return NETDEV_TX_OK;
 
 overflow:
        /*
@@ -2621,8 +2622,15 @@
         * Alternative is to return with 1 not throttling queue. In this
         * case loop becomes longer, no more useful effects.
         */
-       barrier();
-       goto restart;
+       if (time_before(jiffies, maxjiff)) {
+               barrier();
+               cpu_relax();
+               goto restart;
+       }
+       
+       /* The ring is stuck full. */
+       printk(KERN_WARNING "%s: Transmit ring stuck full\n", dev->name);
+       return NETDEV_TX_BUSY;
 }