From: Linus Torvalds <torvalds@linux-foundation.org>
To: Larry Finger <Larry.Finger@lwfinger.net>
Cc: "Gábor Stefanik" <netrolller.3d@gmail.com>,
"John W. Linville" <linville@tuxdriver.com>,
"David S. Miller" <davem@davemloft.net>,
wireless <linux-wireless@vger.kernel.org>,
"Greg Kroah-Hartman" <gregkh@suse.de>
Subject: Re: Make b43 driver fall back gracefully to PIO mode after fatal DMA errors
Date: Fri, 26 Feb 2010 13:45:16 -0800 (PST) [thread overview]
Message-ID: <alpine.LFD.2.00.1002261337460.4513@localhost.localdomain> (raw)
In-Reply-To: <4B8836BF.7000403@lwfinger.net>
On Fri, 26 Feb 2010, Larry Finger wrote:
>
> If you do the following (as root):
>
> modprobe -r b43
> echo 6400 > /sys/kernel/debug/tracing/buffer_size_kb
> echo mmiotrace > /sys/kernel/debug/tracing/current_tracer
> cat /sys/kernel/debug/tracing/trace_pipe > mydump.txt &
> modprobe b43
>
> do some network activity, then
>
> echo nop > /sys/kernel/debug/tracing/current_tracer
> sleep 1
> killproc cat
>
> That should be a good enough test. If your machine behaves the same as has been
> reported, you should see a DMA error at the point that tracing is turned off.
Nope. I get the DMA error immediately, even if I'm tracing. Here:
- turn on tracing:
Feb 26 13:35:45 localhost kernel: mmiotrace: Disabling non-boot CPUs...
Feb 26 13:35:45 localhost kernel: Broke affinity for irq 9
Feb 26 13:35:45 localhost kernel: Broke affinity for irq 12
Feb 26 13:35:45 localhost kernel: Broke affinity for irq 26
Feb 26 13:35:45 localhost kernel: CPU 1 is now offline
Feb 26 13:35:45 localhost kernel: SMP alternatives: switching to UP code
Feb 26 13:35:45 localhost kernel: mmiotrace: CPU1 is down.
Feb 26 13:35:45 localhost kernel: mmiotrace: enabled.
- insmod b43:
Feb 26 13:36:31 localhost kernel: cfg80211: Calling CRDA to update world regulatory domain
...
Feb 26 13:36:31 localhost kernel: b43 ssb0:0: firmware: requesting b43/lp0initvals15.fw
Feb 26 13:36:31 localhost kernel: b43 ssb0:0: firmware: requesting b43/lp0bsinitvals15.fw
Feb 26 13:36:32 localhost kernel: b43-phy0: Loading firmware version 478.104 (2008-07-01 00:50:23)
Feb 26 13:36:34 localhost kernel: b43-phy0 ERROR: Fatal DMA error: 0x00000400, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000
Feb 26 13:36:34 localhost kernel: b43-phy0 ERROR: This device does not support DMA on your system. Please use PIO instead.
Feb 26 13:36:34 localhost kernel: b43-phy0 ERROR: CONFIG_B43_FORCE_PIO must be set in your kernel configuration.
Feb 26 13:36:34 localhost kernel: b43-phy0: Controller RESET (DMA error) ...
Feb 26 13:36:34 localhost kernel: b43-phy0: Loading firmware version 478.104 (2008-07-01 00:50:23)
..
- networking works (because this kernel had the PIO fallback patch)
- turn off tracing:
Feb 26 13:37:15 localhost kernel: mmiotrace: purging non-iounmapped trace @0xffffc90022560000, size 0x4000.
Feb 26 13:37:15 localhost kernel: mmiotrace: Re-enabling CPUs...
Feb 26 13:37:15 localhost kernel: SMP alternatives: switching to SMP code
Feb 26 13:37:15 localhost kernel: Booting Node 0 Processor 1 APIC 0x1
Feb 26 13:37:15 localhost kernel: mmiotrace: enabled CPU1.
Feb 26 13:37:15 localhost kernel: mmiotrace: disabled.
so even if mmiotrace fixes it for others, it's not working for me.
Linus
next prev parent reply other threads:[~2010-02-26 21:46 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <alpine.LFD.2.00.1002261034140.4513@localhost.localdomain>
2010-02-26 19:09 ` Make b43 driver fall back gracefully to PIO mode after fatal DMA errors Larry Finger
2010-02-26 19:13 ` Linus Torvalds
2010-02-26 20:06 ` Linus Torvalds
2010-02-26 20:09 ` Gábor Stefanik
2010-02-26 20:50 ` Linus Torvalds
2010-02-26 21:01 ` Larry Finger
2010-02-26 21:45 ` Linus Torvalds [this message]
2010-02-26 21:50 ` Linus Torvalds
2010-02-26 22:08 ` Gábor Stefanik
2010-02-26 22:46 ` Linus Torvalds
2010-02-26 22:54 ` Gábor Stefanik
2010-02-27 15:04 ` Michael Buesch
2010-02-27 14:59 ` Michael Buesch
2010-02-27 18:31 ` Linus Torvalds
2010-02-27 18:51 ` Michael Buesch
2010-02-26 19:59 ` Michael Buesch
2010-02-26 20:07 ` Linus Torvalds
2010-02-26 20:20 ` Michael Buesch
2010-02-26 20:33 ` Linus Torvalds
2010-02-26 20:42 ` Linus Torvalds
2010-02-27 14:44 ` Michael Buesch
2010-02-27 14:49 ` Michael Buesch
2010-02-27 17:36 ` Michael Buesch
2010-02-27 20:12 ` Nathan Schulte
2010-02-27 21:08 ` Linus Torvalds
2010-02-27 21:43 ` Michael Buesch
2010-02-27 22:12 ` Linus Torvalds
2010-02-26 20:46 Nathan Schulte
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