kaweth: Fix locking to be SMP-safe
On an SMP system, the following message is printed. The patch below gets
fixes the problem.
=================================
[ INFO: inconsistent lock state ]
2.6.29-Linus-05093-gc31f403 #57
---------------------------------
inconsistent {hardirq-on-W} -> {in-hardirq-W} usage.
bash/4105 [HC1[1]:SC0[0]:HE0:SE1] takes:
(&kaweth->device_lock){+...}, at: [<ffffffffa01aa286>]
kaweth_usb_receive+0x77/0x1af [kaw eth]
{hardirq-on-W} state was registered at:
[<ffffffff80260503>] __lock_acquire+0x753/0x1685
[<ffffffff8026148a>] lock_acquire+0x55/0x71
[<ffffffff80461ba6>] _spin_lock+0x31/0x3d
[<ffffffffa01aaa0c>] kaweth_start_xmit+0x2b/0x1e1 [kaweth]
[<ffffffff803eccd3>] dev_hard_start_xmit+0x22e/0x2ad
[<ffffffff803fe120>] __qdisc_run+0xf2/0x203
[<ffffffff803ed0cd>] dev_queue_xmit+0x263/0x39b
[<ffffffffa03a47cb>] packet_sendmsg_spkt+0x1c4/0x20a [af_packet]
[<ffffffff803de0c2>] sock_sendmsg+0xe4/0xfd
[<ffffffff803dec8f>] sys_sendto+0xe4/0x10c
[<ffffffff8020bccb>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
irq event stamp: 1280
hardirqs last enabled at (1279): [<ffffffff80461a71>]
_spin_unlock_irqrestore+0x44/0x4c
hardirqs last disabled at (1280): [<ffffffff8020bad7>]
save_args+0x67/0x70
softirqs last enabled at (660): [<ffffffff8024192c>]
__do_softirq+0x14d/0x15d
softirqs last disabled at (651): [<ffffffff8020ce9c>]
call_softirq+0x1c/0x28
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/kaweth.c b/drivers/net/usb/kaweth.c
index 7cb10a0a..3d0d0b0 100644
--- a/drivers/net/usb/kaweth.c
+++ b/drivers/net/usb/kaweth.c
@@ -36,7 +36,6 @@
* Run test procedures
* Fix bugs from previous two steps
* Snoop other OSs for any tricks we're not doing
- * SMP locking
* Reduce arbitrary timeouts
* Smart multicast support
* Temporary MAC change support
@@ -796,7 +795,7 @@
int res;
- spin_lock(&kaweth->device_lock);
+ spin_lock_irq(&kaweth->device_lock);
kaweth_async_set_rx_mode(kaweth);
netif_stop_queue(net);
@@ -814,7 +813,7 @@
if (!copied_skb) {
kaweth->stats.tx_errors++;
netif_start_queue(net);
- spin_unlock(&kaweth->device_lock);
+ spin_unlock_irq(&kaweth->device_lock);
return 0;
}
}
@@ -848,7 +847,7 @@
net->trans_start = jiffies;
}
- spin_unlock(&kaweth->device_lock);
+ spin_unlock_irq(&kaweth->device_lock);
return 0;
}