Re: [patch] fix suspend/resume on b44

[Andrew Morton <akpm@osdl.org>]

Pavel Machek <pavel@suse.cz> wrote:
>
> Hi!
> 
> > > diff --git a/drivers/net/b44.c b/drivers/net/b44.c
> > > --- a/drivers/net/b44.c
> > > +++ b/drivers/net/b44.c
> > > @@ -1930,6 +1930,8 @@ static int b44_suspend(struct pci_dev *p
> > >  	b44_free_rings(bp);
> > >  
> > >  	spin_unlock_irq(&bp->lock);
> > > +
> > > +	free_irq(dev->irq, dev);
> > >  	pci_disable_device(pdev);
> > >  	return 0;
> > >  }
> > > @@ -1946,6 +1948,9 @@ static int b44_resume(struct pci_dev *pd
> > >  	if (!netif_running(dev))
> > >  		return 0;
> > >  
> > > +	if (request_irq(dev->irq, b44_interrupt, SA_SHIRQ, dev->name, dev))
> > > +		printk(KERN_ERR PFX "%s: request_irq failed\n", dev->name);
> > > +
> > >  	spin_lock_irq(&bp->lock);
> > >  
> > >  	b44_init_rings(bp);
> > > 
> > 
> > Why does it hang on suspend/resume?
> > 
> > This came up a while back and iirc we decided that adding free_irq() to
> > every ->suspend() handler in the world was the wrong thing to do.  Do I
> > misremember?
> 
> No, you remember right, but b44 needed that free_irq/request_irq even
> because those ACPI changes. I'm not exactly sure why, something went
> very wrong otherwise.

Well I guess we should work out what went wrong ;)

What are the symptoms?  Screaming interrupt?  Can't immediately see why. 
Does the screaming interrupt detetor trigger and disable the IRQ Line?