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3c59x: Fix deadlock in vortex_error()

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This fixes a bug introduced in commit
de84727214
"3c59x: Use fine-grained locks for MII and windowed register access".

vortex_interrupt() holds vp->window_lock over multiple register
accesses to reduce locking overhead.  However it also needs to call
vortex_error() sometimes, and that uses the regular functions for
access to windowed registers, which will try to acquire window_lock
again.

Therefore, drop window_lock around the call to vortex_error() and set
the window afterward reacquiring the lock.  Since vortex_error() may
call vortex_rx(), which *does* require its caller to hold window_lock,
lift that call up into vortex_interrupt().  This also removes the
potential for calling vortex_rx() on a later-generation NIC.

Reported-and-tested-by: Jens Schüßler <jgs@trash.net> [in Debian's 2.6.32]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ben Hutchings 2010-09-06 18:28:56 -07:00 committed by David S. Miller
parent 1ee89bd0fe
commit 89b12faba4
1 changed files with 7 additions and 3 deletions
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10
drivers/net/3c59x.c
View File

@ -1994,10 +1994,9 @@ vortex_error(struct net_device *dev, int status)
} }
} }
if (status & RxEarly) { /* Rx early is unused. */ if (status & RxEarly) /* Rx early is unused. */
vortex_rx(dev);
iowrite16(AckIntr | RxEarly, ioaddr + EL3_CMD); iowrite16(AckIntr | RxEarly, ioaddr + EL3_CMD);
}
if (status & StatsFull) { /* Empty statistics. */ if (status & StatsFull) { /* Empty statistics. */
static int DoneDidThat; static int DoneDidThat;
if (vortex_debug > 4) if (vortex_debug > 4)
@ -2298,7 +2297,12 @@ vortex_interrupt(int irq, void *dev_id)
if (status & (HostError | RxEarly | StatsFull | TxComplete | IntReq)) { if (status & (HostError | RxEarly | StatsFull | TxComplete | IntReq)) {
if (status == 0xffff) if (status == 0xffff)
break; break;
if (status & RxEarly)
vortex_rx(dev);
spin_unlock(&vp->window_lock);
vortex_error(dev, status); vortex_error(dev, status);
spin_lock(&vp->window_lock);
window_set(vp, 7);
} }
if (--work_done < 0) { if (--work_done < 0) {