From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Morton <akpm@linux-foundation.org>
Subject: Re: New driver "sfc" for Solarstorm SFC4000 controller.
Date: Tue, 6 May 2008 08:12:25 -0700
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To: Ben Hutchings <bhutchings@solarflare.com>
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On Tue, 6 May 2008 16:04:53 +0100 Ben Hutchings <bhutchings@solarflare.com> wrote:

> > or
> > 
> >  	while (*dma_done != FALCON_STATS_DONE) {
> > 		udelay(1);
> > 		if (++timeout > TIMEOUT)
> > 			goto timeout;
> > 	}
>  
> On some architectures udelay() is defined using inline assembly that is not
> specified as clobbering memory.  So the compiler need not reload *dma_done
> after calling it, and this doesn't work.

So pop a cpu_relax() in there as the document describes?