From: Andy Green <andy@warmcat.com>
To: Stanislav Brabec <utx@penguin.cz>
Cc: Eric Miao <eric.y.miao@gmail.com>,
dbaryshkov@gmail.com, Cyril Hrubis <metan@ucw.cz>,
arminlitzel@web.de, kernel list <linux-kernel@vger.kernel.org>,
Dirk@opfer-online.de, lenz@cs.wisc.edu, rpurdie@rpsys.net,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
Pavel Machek <pavel@ucw.cz>,
thommycheck@gmail.com, zaurus-devel@www.linuxtogo.org,
omegamoon@gmail.com
Subject: Re: bit errors on spitz
Date: Thu, 11 Mar 2010 21:21:37 +0000 [thread overview]
Message-ID: <4B995EE1.1050609@warmcat.com> (raw)
In-Reply-To: <1268322155.3990.114.camel@hammer.suse.cz>
On 03/11/10 15:42, Somebody in the thread at some point said:
> Andy Green wrote:
>
>> I saw very similar failures for a long time on our iMX31 based device.
>> Eventually I found a Freescale errata where the RAM inside the USB2
>> macrocell started to make single bit errors below 1.38V Vcore; ours was
>> 1.4V at that time but dipped on CPU load.
>
> Good tip. It seems that nobody ported driver for the voltage control
> chip ISL6271 from 2.4 kernel, and bootloader probably does not set
> correct values.
>
> Datasheet:
> http://www.penguin.cz/~utx/zaurus/datasheets/power/Xscale/ISL6271.pdf
Unless there's more to it in the way the zaurus using it that regulator
isn't programmable digitally.
Reading about your CF Card WLAN related issues they suck down a good
amount of power when their radio is up, I would definitely suggest
monitoring with a 'scope the various rails (Vcore, RAM and whatever it
is the CF Card is powered by) while putting it under load.
-Andy
next prev parent reply other threads:[~2010-03-11 21:21 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-05 21:27 bit errors on spitz Pavel Machek
2010-03-08 5:37 ` Eric Miao
2010-03-08 7:28 ` Pavel Machek
2010-03-08 8:25 ` Cyril Hrubis
2010-03-08 11:48 ` Stanislav Brabec
2010-03-08 12:16 ` Cyril Hrubis
2010-03-08 12:42 ` Russell King - ARM Linux
2010-03-08 13:32 ` Cyril Hrubis
2010-06-03 0:01 ` [URGENT] Re: bit errors on spitz + voipac Marek Vasut
2010-06-03 2:30 ` Eric Miao
2010-03-21 20:40 ` bit errors on spitz Pavel Machek
2010-03-11 13:25 ` Andy Green
2010-03-11 15:42 ` Stanislav Brabec
2010-03-11 21:21 ` Andy Green [this message]
2010-03-12 9:07 ` Stanislav Brabec
2010-03-12 9:33 ` Andy Green
2010-03-12 10:43 ` Stanislav Brabec
2010-03-12 11:13 ` Andy Green
2010-03-21 20:43 ` Pavel Machek
2010-03-21 21:42 ` Stanislav Brabec
2010-03-29 18:27 ` Pavel Machek
2010-03-29 18:52 ` Stanislav Brabec
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