[PATCH 1/1] fix occasional ULPI timeouts with ehci-mxc

Andy Green andy at warmcat.com
Thu Dec 3 09:53:56 EST 2009


On 12/03/09 14:45, Somebody in the thread at some point said:

Hi Alan -

> On 12/2/09, Andy Green<andy at warmcat.com>  wrote:
>> 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.
>
> The CS_N pin is connected directly to GPIO (PA24) with no pull-up.
>
>> A 10K to your IO voltage rail on CS_N solved it for the LiteKIT and on
>> the boards we have made.
>
> I place a 10K resistor to pull-up and changed CS_N to low at usb
> platform init and it worked fine!
>
> Thank you very much!

You're super welcome... glad that time spent wandering in the desert was 
able to help someone else in the end :-)

-Andy



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