[PATCH] lockdep: annotate bcsp driver

    =============================================
    [ INFO: possible recursive locking detected ]
    2.6.18-1.2699.fc6 #1
    ---------------------------------------------
    swapper/0 is trying to acquire lock:
     (&list->lock#3){+...}, at: [<c05ad307>] skb_dequeue+0x12/0x43

    but task is already holding lock:
     (&list->lock#3){+...}, at: [<df98cd79>] bcsp_dequeue+0x6a/0x11e [hci_uart]

Two different list locks nest, annotate so.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/bluetooth/hci_bcsp.c b/drivers/bluetooth/hci_bcsp.c
index d0cface535fb33e851aeab4548c2bcd6097340dd..5e2c31882003e785f630597d0ba8451d0e195e3a 100644 (file)
--- a/drivers/bluetooth/hci_bcsp.c
+++ b/drivers/bluetooth/hci_bcsp.c
@@ -330,7 +330,7 @@ static struct sk_buff *bcsp_dequeue(struct hci_uart *hu)
           reliable packet if the number of packets sent but not yet ack'ed
           is < than the winsize */
 
-       spin_lock_irqsave(&bcsp->unack.lock, flags);
+       spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
 
        if (bcsp->unack.qlen < BCSP_TXWINSIZE && (skb = skb_dequeue(&bcsp->rel)) != NULL) {
                struct sk_buff *nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len, bt_cb(skb)->pkt_type);
@@ -696,7 +696,7 @@ static void bcsp_timed_event(unsigned long arg)
 
        BT_DBG("hu %p retransmitting %u pkts", hu, bcsp->unack.qlen);
 
-       spin_lock_irqsave(&bcsp->unack.lock, flags);
+       spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
 
        while ((skb = __skb_dequeue_tail(&bcsp->unack)) != NULL) {
                bcsp->msgq_txseq = (bcsp->msgq_txseq - 1) & 0x07;