skge napi->poll() locking bug
authorMarin Mitov <mitov@issp.bas.bg>
Sun, 23 Mar 2008 08:20:09 +0000 (10:20 +0200)
committerJeff Garzik <jeff@garzik.org>
Wed, 26 Mar 2008 03:42:06 +0000 (23:42 -0400)
According to: Documentation/networking/netdevices.txt:

<cite>
napi->poll:
..........
Context: softirq
         will be called with interrupts disabled by netconsole.
</cite>

napi->poll() could be called either with interrupts enabled
(in softirq context) or disabled (by netconsole), so the irq flag
should be preserved.

Inspired by Ingo's resent forcedeth patch :-)

Signed-off-by: Marin Mitov <mitov@issp.bas.bg>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
drivers/net/skge.c

index 186eb8ebfda643e2155579f5d36ad7fc518fb4b6..ae52cba75f9a7dd424f7fed0208785327345320e 100644 (file)
@@ -3199,12 +3199,14 @@ static int skge_poll(struct napi_struct *napi, int to_do)
        skge_write8(hw, Q_ADDR(rxqaddr[skge->port], Q_CSR), CSR_START);
 
        if (work_done < to_do) {
-               spin_lock_irq(&hw->hw_lock);
+               unsigned long flags;
+               
+               spin_lock_irqsave(&hw->hw_lock, flags);
                __netif_rx_complete(dev, napi);
                hw->intr_mask |= napimask[skge->port];
                skge_write32(hw, B0_IMSK, hw->intr_mask);
                skge_read32(hw, B0_IMSK);
-               spin_unlock_irq(&hw->hw_lock);
+               spin_unlock_irqrestore(&hw->hw_lock, flags);
        }
 
        return work_done;