[U-Boot] [RFC] NFS issue when loading two files

[Matthias Brugger <matthias.bgg@gmail.com>]

Hello Wolfgang, hello all,

sorry for re-sending, but the list didn't accept an attachment.

On 12/05/2012 11:20 PM, Wolfgang Denk wrote:
> Dear Matthias Brugger,
>
> In message <50BF9CC3.9020207@gmail.com> you wrote:
>>
>> I run into an NFS issue when trying to load two files from nfs for
>> booting (uImage and device tree binary):
>>
>> When I try to unmount after loading the first file, I get some timeouts
>> from the host which will lead to a re-send of the message.
>> Eventually I get a response from the host, but with a smaller rpc_id, as
>> rpc_id is incremented on every re-send as well. This leads in an abort
>> of the boot procedure, although a valid answer was given from the host.
>
> How do you do the umount in U-Boot?

I wasn't clear on this, sorry.
It seems that u-boot sends a umountall command to the nfs server after 
having received the file.

>
>> [1] the process looks like:
>> mount
>> read file
>> unmount (timed out) #1
>> unmount (timed out) #2
>> unmount
>> get response of #1
>> mount
>> get response of #2
>> error!
>
> What is the exact sequence of U-Boot coomands that would trigger such
> an error?

I use igep0020 board. You can find my uEvent.txt at
http://pastebin.com/6mG6RJmf
Please note that I just load the uImage and the device tree binary from 
nfs, as device tree yet does not support network for my kernel.

If you want, I can send you a wireshark dump I made to analyse the problem.

Later this day I'll send a patch which resolves the issue.
Basically it does not increment rpc_id if a time out leads to a resend 
and it make the state machine drop messages with a lower rpc_id as the 
one in the state machine.

Best regards,
Matthias Brugger

>
> Best regards,
>
> Wolfgang Denk
>