b44: device restarts on heavy load

[Jean-Louis Dupond <info@dupondje.be>]

Hello,

There seems to be a bug in the b44 driver to cause a restart/reset of 
the network card. I tried to debug it a bit, and the error is in the 
b44_poll method.

846 static int b44_poll(struct napi_struct *napi, int budget)
847 {
848         struct b44 *bp = container_of(napi, struct b44, napi);
849         int work_done;
850
851         spin_lock_irq(&bp->lock);
852
853         if (bp->istat & (ISTAT_TX | ISTAT_TO)) {
854                 /* spin_lock(&bp->tx_lock); */
855                 b44_tx(bp);
856                 /* spin_unlock(&bp->tx_lock); */
857         }
858         spin_unlock_irq(&bp->lock);
859
860         work_done = 0;
861         if (bp->istat & ISTAT_RX)
862                 work_done += b44_rx(bp, budget);
863
864         if (bp->istat & ISTAT_ERRORS) {
865                 unsigned long flags;
866
867                 spin_lock_irqsave(&bp->lock, flags);
868                 b44_halt(bp);
869                 b44_init_rings(bp);
870                 b44_init_hw(bp, B44_FULL_RESET_SKIP_PHY);
871                 netif_wake_queue(bp->dev);
872                 spin_unlock_irqrestore(&bp->lock, flags);
873                 work_done = 0;
874         }
875
876         if (work_done < budget) {
877                 napi_complete(napi);
878                 b44_enable_ints(bp);
879         }
880
881         return work_done;
882 }


It seems that suddenly bp->istat & ISTAT_ERRORS is true, so it resets 
the network card. This isn't really nice :(

There seems to be ALOT of people having this issue: 
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/279102

Sincerely
Jean-Louis Dupond