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From: andy@warmcat.com (Andy Green)
To: linux-arm-kernel@lists.infradead.org
Subject: 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

WARNING: multiple messages have this Message-ID (diff)
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

  reply	other threads:[~2010-03-11 21:21 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-05 21:27 bit errors on spitz Pavel Machek
2010-03-05 21:27 ` Pavel Machek
2010-03-08  5:37 ` Eric Miao
2010-03-08  5:37   ` Eric Miao
2010-03-08  7:28   ` Pavel Machek
2010-03-08  7:28     ` Pavel Machek
2010-03-08  8:25     ` Cyril Hrubis
2010-03-08  8:25       ` Cyril Hrubis
2010-03-08 11:48       ` Stanislav Brabec
2010-03-08 11:48         ` Stanislav Brabec
2010-03-08 12:16         ` Cyril Hrubis
2010-03-08 12:16           ` Cyril Hrubis
2010-03-08 12:42           ` Russell King - ARM Linux
2010-03-08 12:42             ` Russell King - ARM Linux
2010-03-08 13:32             ` Cyril Hrubis
2010-03-08 13:32               ` Cyril Hrubis
2010-06-03  0:01           ` [URGENT] Re: bit errors on spitz + voipac Marek Vasut
2010-06-03  0:01             ` Marek Vasut
2010-06-03  2:30             ` Eric Miao
2010-06-03  2:30               ` Eric Miao
2010-03-21 20:40         ` bit errors on spitz Pavel Machek
2010-03-21 20:40           ` Pavel Machek
2010-03-11 13:25       ` Andy Green
2010-03-11 13:25         ` Andy Green
2010-03-11 15:42         ` Stanislav Brabec
2010-03-11 15:42           ` Stanislav Brabec
2010-03-11 21:21           ` Andy Green [this message]
2010-03-11 21:21             ` Andy Green
2010-03-12  9:07             ` Stanislav Brabec
2010-03-12  9:07               ` Stanislav Brabec
2010-03-12  9:33               ` Andy Green
2010-03-12  9:33                 ` Andy Green
2010-03-12 10:43                 ` Stanislav Brabec
2010-03-12 10:43                   ` Stanislav Brabec
2010-03-12 11:13                   ` Andy Green
2010-03-12 11:13                     ` Andy Green
2010-03-21 20:43               ` Pavel Machek
2010-03-21 20:43                 ` Pavel Machek
2010-03-21 21:42                 ` Stanislav Brabec
2010-03-21 21:42                   ` Stanislav Brabec
2010-03-29 18:27                   ` Pavel Machek
2010-03-29 18:27                     ` Pavel Machek
2010-03-29 18:52                     ` Stanislav Brabec
2010-03-29 18:52                       ` Stanislav Brabec

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