Message-ID: <4B8D8CF8.8030003@lwfinger.net>
Date: Tue, 02 Mar 2010 16:11:04 -0600
From: Larry Finger <Larry.Finger@lwfinger.net>
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To: Michael Buesch <mb@bu3sch.de>
CC: Nathan Schulte <reklipz@gmail.com>,
	=?ISO-8859-1?Q?G=E1bor_Stefanik?= <netrolller.3d@gmail.com>,
	bcm43xx-dev@lists.berlios.de, linux-wireless@vger.kernel.org,
	Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: LP-PHY Fatal DMA error 0x00000800 on non-ULV Core 2 Duo?!?!!??!
References: <69e28c911002260708g45d3c0f7u6abf13b1babe549f@mail.gmail.com> <a221c0101002281538p717a3b5v16b14d251cdcc1dc@mail.gmail.com> <201003010122.51341.mb@bu3sch.de> <201003022257.51878.mb@bu3sch.de>
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On 03/02/2010 03:57 PM, Michael Buesch wrote:
> 
> So what's the status on this? I think the fact that the testing patch showed some
> improvement is a clear indicator that something in the PCI-E core init is wrong.
> It's also not surprising that something is going wrong there. The whole PCI-E core
> code basically is undebugged. I wrote most of it long time ago, but I still
> don't have a device that tests it (and probably won't get one anytime soon).
> So I'm really not surprised that there are bugs. There also are missing parts.
> 
> A bug in the PCI-E core code is able to show such behavior, because all memory
> transfers (MMIO and DMA) from the PCI device to the wireless core are translated
> by the PCI-E core.
> I think the whole PCI-E core code has to be audited (also the specs, probably).

You are right about the audit of the PCIe code and specs. Some of the MMIO
sequences found for wl and missing in b43 come from the code described in
http://bcm-v4.sipsolutions.net/PCI-E; however, that code needs to be checked as
at least one routine is missing, I have not yet had a chance to go through it,
but I hope to soon.

Larry