[U-Boot] Slow tftp boot with Ubuntu 12.04 tftp server

[Steve Strobel]

On Thu, Jan 17, 2013 at 8:29 AM, David Aldrich
<David.Aldrich at emea.nec.com>wrote:

> I would like to give some more information about my problem.  u-boot's
> tftp transfers do eventually complete and the evm boots.  I can then
> execute tftp get commands from Linux on the evm and these execute quickly.
> So the problem definitely has to do with the way u-boot uses tftp.
>

I have experienced similar issues.  It seems that once U-Boot's TFTP client
has trouble with one packet that it tends to have a lot more trouble
thereafter.  For example, if the file I try to TFTP doesn't exist when I
start the transfer, it retries until the file does exist at which time it
starts the transfer (so far, so good), but the file transfer is then very
slow.  If I press CTRL-C to stop it then start it again, it runs quickly.

I have also had problems using TFTP from U-Boot through Ethernet hubs that
seem to work well for everything else.  Replacing the hubs with switches
solved the problem in multiple cases.

I haven't tried to capture the packets and troubleshoot it, but it seems
like there is something non-optimal in the timing.

Steve


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Steve Strobel
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