From: Michael Buesch <mb@bu3sch.de>
To: Chris Vine <chris@cvine.freeserve.co.uk>
Subject: Re: DMA errors with BCM4312 - an update
Date: Tue, 24 Nov 2009 22:20:45 +0100
Cc: Larry Finger <Larry.Finger@lwfinger.net>,
	bcm43xx devel <Bcm43xx-dev@lists.berlios.de>,
	wireless <linux-wireless@vger.kernel.org>,
	Michael Buesch <mb@bu3sch.df>,
	William Bourque <william.bourque@polymtl.ca>
References: <4B0C2EC3.5010408@lwfinger.net> <20091124211552.533a2b4e@boulder.homenet>
In-Reply-To: <20091124211552.533a2b4e@boulder.homenet>
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On Tuesday 24 November 2009 22:15:52 Chris Vine wrote:
> On Tue, 24 Nov 2009 13:06:43 -0600
> Larry Finger <Larry.Finger@lwfinger.net> wrote:
> > This E-mail is to summarize what I have learned to date.
> > 
> > The pm_qos change does nothing useful. It may have helped a little,
> > but the side effects are far worse than the benefits.
> > 
> > Most systems work better with b43 when warm booted after Broadcom's
> > wl driver was loaded. The conclusion is that wl is making some change
> > in the setup that b43 is not.
> > 
> > (3) Based on the above, I have done MMIO and PCI-E configuration
> > tracing for the two drivers and found some real differences. After
> > seeing these, I did more RE work, and found some setup for the PCI-E
> > core that was missed earlier. I am still working on the changes. What
> > I have completed is found at
> > 
> > http://bcm-v4.sipsolutions.net/PCI-E#PCI-E_Setup
> > 
> > I doubt that most of these new routines will affect the problem
> > interfaces as they apply only to PCI-E core revisions 7 and 8. My
> > BCM4312 has rev 9. I do not know what versions are giving the
> > trouble. With SSB_DEBUG enabled, it will be in a log line as follows:
> > 
> > ssb: Core 3 found: PCI-E (cc 0x820, rev 0x09, vendor 0x4243)
> > 
> > If you are seeing the DMA error, please supply the above info.
> > 
> > The "PCI-E Miscellaneous Configuration" routine that is not yet
> > finished does run on my system and is the source of the tracing
> > differences. If the problem cards has a revision newer than 9, I will
> > probably need an MMIO trace for your device.
> 
> This is mine, the same revision as yours, but which demonstrates the
> DMA errors:
> 
> ssb: Core 0 found: ChipCommon (cc 0x800, rev 0x16, vendor 0x4243)
> ssb: Core 1 found: IEEE 802.11 (cc 0x812, rev 0x0F, vendor 0x4243)
> ssb: Core 2 found: PCMCIA (cc 0x80D, rev 0x0A, vendor 0x4243)
> ssb: Core 3 found: PCI-E (cc 0x820, rev 0x09, vendor 0x4243)
> ssb: Found rev 1 PMU (capabilities 0x02A62F01)

Larry, do you also have the same PMU?

-- 
Greetings, Michael.