On Fri, 12 May 2006, Andrew Morton wrote:
> Steven Rostedt <[email protected]> wrote:
> >
> > Use this patch instead. It needs an irq disable. But, believe it or not,
> > on SMP this is actually better. If the irq is shared (as it is in Mark's
> > case), we don't stop the irq of other devices from being handled on
> > another CPU (unfortunately for Mark, he pinned all interrupts to one CPU).
> >
> > Andrew,
> >
> > should this be changed in mainline too?
>
> I suppose so - we're taking the lock with spin_lock_bh(), but it can also
> be taken by this CPU from the interrupt, so it'll deadlock. But lo! We've
> done disable_irq(), so the interrupt won't be happening.
>
> So yes, doing spin_lock_irq() (irqrestore isn't needed in a timer handler)
> instead of disable_irq() in vortex_timer() looks OK.
Ah, you're right, it's an over kill.
Ingo, here's the patch without irqsave
-- Steve
Index: linux-2.6.16-rt20/drivers/net/3c59x.c
===================================================================
--- linux-2.6.16-rt20.orig/drivers/net/3c59x.c 2006-05-12 10:27:36.000000000 -0400
+++ linux-2.6.16-rt20/drivers/net/3c59x.c 2006-05-12 11:03:39.000000000 -0400
@@ -1897,7 +1897,7 @@ vortex_timer(unsigned long data)
if (vp->medialock)
goto leave_media_alone;
- disable_irq(dev->irq);
+ spin_lock_irq(&vp->lock);
old_window = ioread16(ioaddr + EL3_CMD) >> 13;
EL3WINDOW(4);
media_status = ioread16(ioaddr + Wn4_Media);
@@ -1919,7 +1919,6 @@ vortex_timer(unsigned long data)
break;
case XCVR_MII: case XCVR_NWAY:
{
- spin_lock_bh(&vp->lock);
mii_status = mdio_read(dev, vp->phys[0], MII_BMSR);
if (!(mii_status & BMSR_LSTATUS)) {
/* Re-read to get actual link status */
@@ -1957,7 +1956,6 @@ vortex_timer(unsigned long data)
} else {
netif_carrier_off(dev);
}
- spin_unlock_bh(&vp->lock);
}
break;
default: /* Other media types handled by Tx timeouts. */
@@ -2000,7 +1998,7 @@ vortex_timer(unsigned long data)
/* AKPM: FIXME: Should reset Rx & Tx here. P60 of 3c90xc.pdf */
}
EL3WINDOW(old_window);
- enable_irq(dev->irq);
+ spin_unlock_irq(&vp->lock);
leave_media_alone:
if (vortex_debug > 2)
-
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