Subject: Re: MTD driver cleanup
To: Peter Bex <>
From: Martin Husemann <>
List: tech-kern
Date: 07/01/2003 23:18:23
On Tue, Jul 01, 2003 at 05:04:29PM +0200, Peter Bex wrote:
> When I created the driver, I put in a debugging message in mtd803.c, lines
> 463 through 465. This is certainly not something one would like in a production
> system. (The messages are quite numerous)

This is because you did not tell the system to use small enough MTU or you
are using the hardware suboptimal.

You could try to set ifp->if_mtu = MTD_TXBUF_SIZE before calling if_attach/
ether_ifattach. But see below.

> It simply ignores packets which are
> too large right now. Is this correct behaviour?

Yes, you could merge that case with the len == 0 case above.

All in all it sounds *very* strange that a ethernet card would not be
able to send full sized ethernet frames. Can you configure the hardware to
use less, but bigger buffers (i.e. have 64 buffers of 1536 byte, which would
incidently be ETHERMTU + header + CRC)?