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From: Larry Finger <Larry.Finger@lwfinger.net>
To: Nathan Hintz <nlhintz@hotmail.com>
Cc: linux-wireless@vger.kernel.org
Subject: Re: brcmsmac: Data bus error in reading tsf_random
Date: Mon, 03 Dec 2012 10:19:28 -0600	[thread overview]
Message-ID: <50BCD110.6050803@lwfinger.net> (raw)
In-Reply-To: <loom.20121203T054035-582@post.gmane.org>

On 12/02/2012 10:47 PM, Nathan Hintz wrote:

> I encountered a similar DBE using the "broadcom-wl" driver (OpenWRT) on a
> Linksys E3000; except that it occurred when reading "ifs_ctl" (offset 0x688).
> I too tried putting in some printk's (in linux_osl.c), which caused the
> problem to go away.  I eventually found that doing a dummy read of 4 bytes
> at that particular address just prior to the actual two byte read caused
> the problem to go away as well (an ugly hack).  I can reproduce it if you
> want a stack trace.

Does an ndelay(xx), with xx of 10 or so, be as effective as the dummy read? It 
is not a lot less of a hack, but it would indicate the source of the problem.

Larry


  reply	other threads:[~2012-12-03 16:19 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-02  1:36 brcmsmac: Data bus error in reading tsf_random Hauke Mehrtens
2012-12-03  4:47 ` Nathan Hintz
2012-12-03 16:19   ` Larry Finger [this message]
2012-12-03 20:40 ` Arend van Spriel

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