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ronwright2013
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‎04-20-2015 09:54 AM

7,865 Views
Registered: ‎10-09-2013

PetaLinux u-boot and USB timeout

I've modified the standard u-boot configuration under PetaLinux 2014.4 to include USB support, in order to use a plug-in device as a source for secondary boot file.  All works well until I try to read from the USB device (I've tried several sticks and a USB HD) and all fail with the message:

 

"ECHI timed out on TD - token = <0xnnnnnnnn>"

 

I found some documentation that indicated this can happen with "older" USB devices, and it is necessary to change the u-boot code to compensate.  I searched patch information and found a couple of files (usb.h and ehci-hcd.c) in the u-boot hierarchy that looked promising, but no matter how large I make the timeouts I get the same error and the read fails.

 

Has anyone been able to successfully read from a USB device from PetaLinux u-boot?  Are there other files I should be looking to modify, or any more details on the changes required?

 

Thanks,

 

Ron

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ronwright2013
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‎04-27-2015 03:35 PM

7,814 Views
Registered: ‎10-09-2013

It turns out that the USB read does actually work for files up to about 5 MB.  However, files larger than that approximate threshold end up with the ECHI timeout messages and the reads fail.  I tried this with several different USB devices and the results are fairly consistent.

 

So it looks like this could be related to a buffer somewhere in the u-boot code?

 

Ron

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