From mboxrd@z Thu Jan  1 00:00:00 1970
From: valentin.longchamp@epfl.ch (Valentin Longchamp)
Date: Thu, 03 Dec 2009 09:03:27 +0100
Subject: [PATCH 1/1] fix occasional ULPI timeouts with ehci-mxc
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To: linux-arm-kernel@lists.infradead.org
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Hi all,

Andy Green wrote:
> On 12/02/09 20:25, Somebody in the thread at some point said:
> 
>>> What did you do with your chip select line on the ULPI PHY?
>> I turn this line (CS_N) low before initializing ISP1504.
> 
> It's more a question about what that input on the PHY chip sees during 
> powerup / reset... it needs to be nicely and definitely high the whole 
> time so it will ignore what happens then.  Is it pulled up, or just 
> connected to the iMX GPIO?  iMX GPIO alone may not be enough.  They 
> mostly default to 100K pullup but even that may not be enabled early in 
> the powerup action.
> 
> A 10K to your IO voltage rail on CS_N solved it for the LiteKIT and on 
> the boards we have made.
> 

I just wanted to point out that we also have a 10K pull-up on the CS_N 
on our boards, it helps a lot.

Val

-- 
Valentin Longchamp, PhD Student, EPFL-STI-LSRO1
valentin.longchamp at epfl.ch, Phone: +41216937827
http://people.epfl.ch/valentin.longchamp
MEA3485, Station 9, CH-1015 Lausanne