[U-Boot] Question about Netconsole

[Detlev Zundel]

Hi Jared,

> I have been having troubles getting Netconsole to work on eTSEC2 of a
> MPC8548 chip.  I was hoping that maybe someone here might be able to
> help me. 
>
> I'm currently using U-Boot v2009.01.  Using the bash script code located
> in the README.Netconsole file, I have been able to successfully transmit
> data from the 8548 to my host machine over netcat (using v0.7.1 on
> Fedora Core 11).  I've tested that this path works consistently by only
> piping stdout to 'nc'.  
>
> My problem comes when I try to send data from the host machine to the
> 8548 (piping stdin to 'nc').  It seems like the data is getting
> transmitted by Netconsole (verified using wireshark), but it isn't
> getting consistently received by U-Boot.  I set the ET_DEBUG flag to 1
> so that I could get extra debug information.  On rare occasions I have
> seen that packets are getting received, but this is very rarely.  I do
> know that the connection is OK.  I am able to transfer files using tftp
> without any problems.  On one occasion I was able to print out an
> environment variable (a small victory), but it happened randomly.  
>
> Does anyone have any idea why this might be happening?  Any help would
> be greatly appreciated.

You should check what your actual network driver is doing.  As U-Boot is
not interrupt driven, the big question is if and how packets on the network
interface are buffered when U-Boot is not currently idle waiting.

Unfortunately I have to admit that I do not know the exact control flow
of netconsole coupled to the tsec driver, but what you could do is to
trace tsec_halt and startup_tsec.  Maybe they are called too often and/or
take too long...

Cheers
  Detlev

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