[Top] [All Lists]

Re: [PATCH] Comments in the titan ethernet driver for IP header alignme

To: Thomas Koeller <>
Subject: Re: [PATCH] Comments in the titan ethernet driver for IP header alignment
From: Manish Lachwani <>
Date: Tue, 23 Nov 2004 10:23:11 -0800
Cc: Manish Lachwani <>,,
In-reply-to: <>
Original-recipient: rfc822;
References: <> <>
User-agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4.2) Gecko/20040308
Hi Thomas,

Thomas Koeller wrote:
Hi Manish,

register 0x103c is not documented in any but the newest version of
the processor's user manual, and the function documented there has
_nothing_ to do with header alignment.

I agree. The document says nothing about IP header alignment. And like I said before, this code has been written based on feedback from the chip designers. I have no idea why there is not document describing this, as yet.

So either the docs are wrong,
or the register implements both the documented and undocumented
functions. In this case, however, the code would be wrong because it
permanently modifies the register's contents, which could screw up
packet priority processing.

The code implements sequence of operations that are needed for the chip to align IP headers. Thats all. Now, if you think that this can screw up packet priority processing in any way, then you should point PMC about this potential bug. AFAIK, there are other OS's that use this register to fix the IP header alignment issue on the Titan.

Manish Lachwani


On Tuesday 23 November 2004 18:14, Manish Lachwani wrote:

Hi Ralf,

Attached patch puts comments around the section that programs register
0x103C for IP header alignment. Please review ...

Manish Lachwani

<Prev in Thread] Current Thread [Next in Thread>