Jumbo ethernet frames on MVME6100

Jumbo ethernet frames on MVME6100

[Martin, Tim]

I'm using Linux 2.6.6 with the Motorola Computer Group patch for the
MVME6100 available at

https://mcg.motorola.com/cfm/templates/swDetails.cfm?PageID=3D704&Softwar=
e
ID=3D6&ProductID=3D202

and compiling with GCC from ELDK 3.1.1, although using the userspace
module utils (e.g. insmod) from ELDK 4.0.

The patch includes support for the Marvel gigabit ethernet part on the
board (MV64360?) which works for non-jumbo ethernet frames, but doesn't
receive (or even generate errors) if I send jumbo-ethernet frames.  I
haven't debugged this issue very long, but a cursory look through the
driver hints that jumbo frame support should be on (the port config
serial register PCSR has what I imagine to be okay bits).

I'm ifconfiging the 2nd ethernet device with the command
ifconfig eth1 mtu 9000 192.168.1.1

I'm wondering if anyone else using an MVME6100 has gotten jumbo frame
support to work?

Also, at what point did the Linux 2.6 kernel embedded PPC support start
working with GCC 4.x (e.g. GCC in ELDK 4.0).  I'm getting compiler
errors when I use GCC 4.x with this version of the kernel.

Tim

Re: Jumbo ethernet frames on MVME6100

[Brent Cook]

On Friday 09 June 2006 19:57, Martin, Tim wrote:
> I'm using Linux 2.6.6 with the Motorola Computer Group patch for the
> MVME6100 available at
>
> https://mcg.motorola.com/cfm/templates/swDetails.cfm?PageID=704&Software
> ID=6&ProductID=202
>
> and compiling with GCC from ELDK 3.1.1, although using the userspace
> module utils (e.g. insmod) from ELDK 4.0.

> The patch includes support for the Marvel gigabit ethernet part on the
> board (MV64360?) which works for non-jumbo ethernet frames, but doesn't
> receive (or even generate errors) if I send jumbo-ethernet frames.  I
> haven't debugged this issue very long, but a cursory look through the
> driver hints that jumbo frame support should be on (the port config
> serial register PCSR has what I imagine to be okay bits).
>
> I'm ifconfiging the 2nd ethernet device with the command
> ifconfig eth1 mtu 9000 192.168.1.1
>
> I'm wondering if anyone else using an MVME6100 has gotten jumbo frame
> support to work?

I can say that the MV64x60 ethernet driver that got rolled into the mainline 
kernel around the 2.6.11/12 timeframe does support jumbo frames for send and 
receive. If that patch is anything like some patches I've seen for similar 
products (based on old Marvel/Galileo reference code), I'd say your best-off 
cherry-picking the HW-specific bits from the patch and trying to either 
forward-port/add from scratch the board support to something >= 2.6.12 and 
getting the improved MV64x60 support as a bonus, or backporting at least the 
newer MV ethernet driver. Not only is the newer one _much_ simpler and easier 
to read (like 3 or 4x shorter), but it would appear to work better as well.

> Also, at what point did the Linux 2.6 kernel embedded PPC support start
> working with GCC 4.x (e.g. GCC in ELDK 4.0).  I'm getting compiler
> errors when I use GCC 4.x with this version of the kernel.

No problems here with 2.6.11 through 17-rc6 on gcc 4.

 - Brent