Subject: Re: [PATCH] libata: Add MMIO support to pata_sil680
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reply-To: benh@kernel.crashing.org
To: Jeff Garzik <jeff@garzik.org>
Cc: Tim Ellis <tim@ngndg.com>, Guennadi Liakhovetski <g.liakhovetski@gmx.de>,
       Alan Cox <alan@lxorguk.ukuu.org.uk>, linux-kernel@vger.kernel.org
In-Reply-To: <47C347C3.40404@garzik.org>
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Date: Tue, 26 Feb 2008 11:58:22 +1100
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> Yes.
> 
> Alan loves to complain about lack of MMIO flush, but in practice this is 
> rarely the source of problems such as the one you describe.
> 
> But if its broken its broken, and we need to revert.  Any luck getting 
> benh access to the device?
> 

Especially since reverting it will break a whole bunch of cell blades,
which wouldn't be nice (those cannot do PIO and have that controller).

In the meantime, we might "workaround" with a hack to only enable MMIO
on those cell
blades, something like:

#ifdef CONFIG_PPC64
	if (machine_is(cell))
		mmio = 1;
#endif

That might get us out of the regression until we find the proper
solution ?

Cheers,
Ben.


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