i4l: Fix random hard freeze with AVM c4 card
The patch
- Includes the call to capilib_data_b3_req in the spinlock. This routine
in turn calls the offending mq_enqueue routine that triggered the
freeze if not locked. This should also fix other indicators of
incosistent capilib_msgidqueue list, that trigger messages like:
Oct 5 03:05:57 BERL0 kernel: kcapi: msgid 3019 ncci 0x30301 not on queue
that we saw several times a day (usually several in a row).
- Fixes all occurrences of c4_dispatch_tx to be called with active
spinlock, there were some instances where no lock was active. Mostly
these are in very infrequently called routines, so the additional
performance penalty is minimal.
Signed-off-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Rainer Brestan <rainer.brestan@frequentis.com>
Signed-off-by: Ralf Schlatterbeck <rsc@runtux.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/isdn/hardware/avm/c4.c b/drivers/isdn/hardware/avm/c4.c
index d58f927..8710cf6 100644
--- a/drivers/isdn/hardware/avm/c4.c
+++ b/drivers/isdn/hardware/avm/c4.c
@@ -727,6 +727,7 @@
{
struct sk_buff *skb;
void *p;
+ unsigned long flags;
skb = alloc_skb(15, GFP_ATOMIC);
if (!skb) {
@@ -744,12 +745,15 @@
skb_put(skb, (u8 *)p - (u8 *)skb->data);
skb_queue_tail(&card->dma->send_queue, skb);
+ spin_lock_irqsave(&card->lock, flags);
c4_dispatch_tx(card);
+ spin_unlock_irqrestore(&card->lock, flags);
}
static int queue_sendconfigword(avmcard *card, u32 val)
{
struct sk_buff *skb;
+ unsigned long flags;
void *p;
skb = alloc_skb(3+4, GFP_ATOMIC);
@@ -766,7 +770,9 @@
skb_put(skb, (u8 *)p - (u8 *)skb->data);
skb_queue_tail(&card->dma->send_queue, skb);
+ spin_lock_irqsave(&card->lock, flags);
c4_dispatch_tx(card);
+ spin_unlock_irqrestore(&card->lock, flags);
return 0;
}
@@ -986,7 +992,9 @@
struct sk_buff *skb;
void *p;
+ spin_lock_irqsave(&card->lock, flags);
capilib_release_appl(&cinfo->ncci_head, appl);
+ spin_unlock_irqrestore(&card->lock, flags);
if (ctrl->cnr == card->cardnr) {
skb = alloc_skb(7, GFP_ATOMIC);
@@ -1019,7 +1027,8 @@
u16 retval = CAPI_NOERROR;
unsigned long flags;
- if (CAPIMSG_CMD(skb->data) == CAPI_DATA_B3_REQ) {
+ spin_lock_irqsave(&card->lock, flags);
+ if (CAPIMSG_CMD(skb->data) == CAPI_DATA_B3_REQ) {
retval = capilib_data_b3_req(&cinfo->ncci_head,
CAPIMSG_APPID(skb->data),
CAPIMSG_NCCI(skb->data),
@@ -1027,10 +1036,9 @@
}
if (retval == CAPI_NOERROR) {
skb_queue_tail(&card->dma->send_queue, skb);
- spin_lock_irqsave(&card->lock, flags);
c4_dispatch_tx(card);
- spin_unlock_irqrestore(&card->lock, flags);
}
+ spin_unlock_irqrestore(&card->lock, flags);
return retval;
}