rt2x00: Upgrade queue->lock to use irqsave
The queue->lock could be grabbed from interrupt context,
which could lead to lockdep panic like this:
kernel: ======================================================
kernel: [ INFO: soft-safe -> soft-unsafe lock order detected ]
kernel: 2.6.25-0.95.rc4.fc9 #1
kernel: ------------------------------------------------------
kernel: rt2500pci/1251 [HC0[0]:SC0[1]:HE1:SE0] is trying to acquire:
kernel: (&queue->lock){--..}, at: [<ffffffff88213339>] rt2x00queue_get_entry+0x5a/0x81 [rt2x00lib]
kernel:
kernel: and this task is already holding:
kernel: (_xmit_IEEE80211){-...}, at: [<ffffffff8122e9a3>] __qdisc_run+0x84/0x1a9
kernel: which would create a new lock dependency:
kernel: (_xmit_IEEE80211){-...} -> (&queue->lock){--..}
kernel:
kernel: but this new dependency connects a soft-irq-safe lock:
kernel: (_xmit_ETHER){-+..}
kernel: ... which became soft-irq-safe at:
kernel: [<ffffffffffffffff>] 0xffffffffffffffff
kernel:
kernel: to a soft-irq-unsafe lock:
kernel: (&queue->lock){--..}
kernel: ... which became soft-irq-unsafe at:
kernel: ... [<ffffffff810545a2>] __lock_acquire+0x62d/0xd63
kernel: [<ffffffff81054d36>] lock_acquire+0x5e/0x78
kernel: [<ffffffff812a1497>] _spin_lock+0x26/0x53
kernel: [<ffffffff88212f98>] rt2x00queue_reset+0x16/0x40 [rt2x00lib]
kernel: [<ffffffff88212fd4>] rt2x00queue_alloc_entries+0x12/0xab [rt2x00lib]
kernel: [<ffffffff88213091>] rt2x00queue_initialize+0x24/0xf2 [rt2x00lib]
kernel: [<ffffffff88212036>] rt2x00lib_start+0x3b/0xd4 [rt2x00lib]
kernel: [<ffffffff88212609>] rt2x00mac_start+0x18/0x1a [rt2x00lib]
kernel: [<ffffffff881b9a4b>] ieee80211_open+0x1f3/0x46d [mac80211]
kernel: [<ffffffff8121d980>] dev_open+0x4d/0x8b
kernel: [<ffffffff8121d41e>] dev_change_flags+0xaf/0x172
kernel: [<ffffffff81224fc2>] do_setlink+0x276/0x338
kernel: [<ffffffff81225198>] rtnl_setlink+0x114/0x116
kernel: [<ffffffff812262fc>] rtnetlink_rcv_msg+0x1d8/0x1f9
kernel: [<ffffffff8123649a>] netlink_rcv_skb+0x3e/0xac
kernel: [<ffffffff8122611a>] rtnetlink_rcv+0x29/0x33
kernel: [<ffffffff81235eed>] netlink_unicast+0x1fe/0x26b
kernel: [<ffffffff81236224>] netlink_sendmsg+0x2ca/0x2dd
kernel: [<ffffffff812103b3>] sock_sendmsg+0xfd/0x120
kernel: [<ffffffff812105a8>] sys_sendmsg+0x1d2/0x23c
kernel: [<ffffffff8100c1c7>] tracesys+0xdc/0xe1
kernel: [<ffffffffffffffff>] 0xffffffffffffffff
This can be fixed by using the irqsave/irqrestore versions
during the queue->lock handling.
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2x00debug.c b/drivers/net/wireless/rt2x00/rt2x00debug.c
index 21af11a..bfab3b8 100644
--- a/drivers/net/wireless/rt2x00/rt2x00debug.c
+++ b/drivers/net/wireless/rt2x00/rt2x00debug.c
@@ -278,6 +278,7 @@
{
struct rt2x00debug_intf *intf = file->private_data;
struct data_queue *queue;
+ unsigned long irqflags;
unsigned int lines = 1 + intf->rt2x00dev->data_queues;
size_t size;
char *data;
@@ -294,7 +295,7 @@
sprintf(data, "qid\tcount\tlimit\tlength\tindex\tdone\tcrypto\n");
queue_for_each(intf->rt2x00dev, queue) {
- spin_lock(&queue->lock);
+ spin_lock_irqsave(&queue->lock, irqflags);
temp += sprintf(temp, "%d\t%d\t%d\t%d\t%d\t%d\t%d\n", queue->qid,
queue->count, queue->limit, queue->length,
@@ -302,7 +303,7 @@
queue->index[Q_INDEX_DONE],
queue->index[Q_INDEX_CRYPTO]);
- spin_unlock(&queue->lock);
+ spin_unlock_irqrestore(&queue->lock, irqflags);
}
size = strlen(data);