Re: b44: regression in 2.6.22 (resend)

Michael Buesch
2007-05-28T14:56:25Z

On Monday 28 May 2007 16:12:12 Maximilian Engelhardt wrote:
> On Monday 28 May 2007, Michael Buesch wrote:
> > Can you also test the following patch?
> > I think there's a bug in b44 that is doesn't properly discard
> > shared IRQs, so it might possibly generate a NAPI storm, dunno.
> > Worth a try.
> >
> > Index: linux-2.6.22-rc3/drivers/net/b44.c
> > ===================================================================
> > --- linux-2.6.22-rc3.orig/drivers/net/b44.c 2007-05-27 23:01:44.000000000
> > +0200 +++ linux-2.6.22-rc3/drivers/net/b44.c 2007-05-28 12:48:27.000000000
> > +0200 @@ -911,6 +911,8 @@ static irqreturn_t b44_interrupt(int irq
> > spin_lock(&bp->lock);
> >
> > istat = br32(bp, B44_ISTAT);
> > + if (istat == 0xFFFFFFFF)
> > + goto out; /* Shared IRQ not for us */
> > imask = br32(bp, B44_IMASK);
> >
> > /* The interrupt mask register controls which interrupt bits
> > @@ -942,6 +944,7 @@ irq_ack:
> > bw32(bp, B44_ISTAT, istat);
> > br32(bp, B44_ISTAT);
> > }
> > +out:
> > spin_unlock(&bp->lock);
> > return IRQ_RETVAL(handled);
> > }
>
> I did try this patch on a affected kernel, but I didn't notice any big
> difference. Perhaps the kernel is a bit less slow during the test, but It's
> hard to tell.

Ok, but anyway. I think this is a bug and needs to be fixed this way. Gary?

--
Greetings Michael.