From mboxrd@z Thu Jan  1 00:00:00 1970
Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 24 Oct 2011 14:19:15 +0200 (CEST)
Received: from eu1sys200aog116.obsmtp.com ([207.126.144.141]:39988 "EHLO
        eu1sys200aog116.obsmtp.com" rhost-flags-OK-OK-OK-OK)
        by eddie.linux-mips.org with ESMTP id S1491071Ab1JXMTJ (ORCPT
        <rfc822;linux-mips@linux-mips.org>); Mon, 24 Oct 2011 14:19:09 +0200
Received: from beta.dmz-eu.st.com ([164.129.1.35]) (using TLSv1) by eu1sys200aob116.postini.com ([207.126.147.11]) with SMTP;
        Mon, 24 Oct 2011 12:19:08 UTC
Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9])
        by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 0BB72139;
        Mon, 24 Oct 2011 12:19:00 +0000 (GMT)
Received: from mail7.sgp.st.com (mail7.sgp.st.com [164.129.223.81])
        by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 6A9872181;
        Mon, 24 Oct 2011 12:19:00 +0000 (GMT)
Received: from [10.52.139.57] (ctn000522.ctn.st.com [10.52.139.57])
        by mail7.sgp.st.com (MOS 4.1.8-GA)
        with ESMTP id AKG03689 (AUTH cavagiu);
        Mon, 24 Oct 2011 14:18:59 +0200
Message-ID: <4EA557B2.4020504@st.com>
Date:   Mon, 24 Oct 2011 14:18:58 +0200
From:   Giuseppe CAVALLARO <peppe.cavallaro@st.com>
User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:7.0.1) Gecko/20110929 Thunderbird/7.0.1
MIME-Version: 1.0
To:     Kelvin Cheung <keguang.zhang@gmail.com>
Cc:     Wu Zhangjin <wuzhangjin@gmail.com>, linux-mips@linux-mips.org,
        linux-kernel@vger.kernel.org, ralf@linux-mips.org,
        r0bertz@gentoo.org, netdev@vger.kernel.org
Subject: Re: [PATCH V2 2/4] MIPS: Add board support for Loongson1B
References: <1319192888-21465-1-git-send-email-keguang.zhang@gmail.com> <1319192888-21465-2-git-send-email-keguang.zhang@gmail.com> <CAD+V5YKBkW52_md9rBeVZ1RXq2FGEXt=Ergsw+z8txMreZdNsA@mail.gmail.com> <4EA5117C.3000402@st.com> <CAJhJPsVSzXXmBOwLaGNtOsxhVEyC0fAJtiBvEWzcKcSDC8NEcA@mail.gmail.com>
In-Reply-To: <CAJhJPsVSzXXmBOwLaGNtOsxhVEyC0fAJtiBvEWzcKcSDC8NEcA@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
X-archive-position: 31291
X-ecartis-version: Ecartis v1.0.0
Sender: linux-mips-bounce@linux-mips.org
Errors-to: linux-mips-bounce@linux-mips.org
X-original-sender: peppe.cavallaro@st.com
Precedence: bulk
X-list: linux-mips
Return-Path: <linux-mips-bounce@linux-mips.org>
X-Keywords:                  
X-UID: 17131

Hello Kelvin.

On 10/24/2011 12:36 PM, Kelvin Cheung wrote:

[snip]

> According to datasheet of Loongson 1B, the buffer size in RX/TX 
> descriptor is only 2KB. So the Loongson1B's GMAC could not handle
> jumbo frames. And the second buffer is useless in this case. Am I
> right? Is there a better way than ifdef CONFIG_MACH_LOONGSON1 to
> avoid duplicate code?

Sorry for my misunderstanding.

I think you have to use the normal descriptor and remove the enh_desc
from the platform w/o modifying the driver at all.

The driver will be able to select/configure all automatically (also jumbo).

Let me know.

Note:
IIRC, there is a bit difference in case of normal descriptors for
Synopsys databook newer than the 1.91 (I used for testing this mode).
In any case, I remember that, on some platforms, the normal descriptors
have been used w/o problems also on these new chip generations.

Peppe