linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Scott Wood <scottwood@freescale.com>
To: embedded <embedded@akb.net>
Cc: linuxppc-embedded@ozlabs.org
Subject: Re: FCC1 failing on large packet PINGS, while FCC2 is successful
Date: Mon, 29 Sep 2008 09:43:13 -0500	[thread overview]
Message-ID: <48E0E981.60703@freescale.com> (raw)
In-Reply-To: <bfa0697f0809261600p7e1af4a6va360d0782cec8257@mail.gmail.com>

embedded wrote:
> We've found a way to get ping to fail all of the time by increasing
> the size of the ping messages.  When we use the max in Windows of
> 65500, every ping to the first FCC1 Ethernet is dropped.  However,
> when we ping with a size of 65500 to the second FCC2 Ethernet
> everything is fine and all echos are successful.
> 
> In windows:
> ping -l 64000 172.24.100.11  -t
> 
> It definitely seems to be a problem with the mpc, but I'm not sure
> where to look.  Board? KErnel? boot loader?  The two Ethernet devices
> should be configured identically, and looking through the kernel code,
> it seems that there aren't any preferred treatment differences.  Could
> the problem be in the bit-banging mdio control, or should I look
> within fs_enet?  We've got this reproducing on all of our boards and
> it could also reside in the board setup...
> 
> Does anyone with experience on the ep8248 and/or mpc8272 family,
> fs_enet-* code have any ideas where I should look next?

It looks very similar to what I was seeing on ep8248 -- the first 
ethernet port would fail when attempting to receive back-to-back 
packets.  I didn't look into it too closely since I thought it was 
probably a board issue (I had only one, and the firmware never generated 
any traffic that resulted in back-to-back receives).

I'd be very interested if you ever figure out what's wrong.

-Scott

  reply	other threads:[~2008-09-30  6:03 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-09-26 23:00 FCC1 failing on large packet PINGS, while FCC2 is successful embedded
2008-09-29 14:43 ` Scott Wood [this message]
2008-09-30 16:46   ` embedded
2008-09-30 16:49     ` Scott Wood

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=48E0E981.60703@freescale.com \
    --to=scottwood@freescale.com \
    --cc=embedded@akb.net \
    --cc=linuxppc-embedded@ozlabs.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).