From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH v2] sh_eth: use RNC mode for R8A7790/R87791 Date: Tue, 03 Jun 2014 00:55:38 +0400 Message-ID: <538CE4CA.4090301@cogentembedded.com> References: <1401729456-23514-1-git-send-email-ben.dooks@codethink.co.uk> <20140602.115303.1283021229124256917.davem@davemloft.net> <538CD19B.5060208@cogentembedded.com> <20140602.134915.1162774321657125992.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: ben.dooks@codethink.co.uk, linux-kernel@codethink.co.uk, netdev@vger.kernel.org, nobuhiro.iwamatsu.yj@renesas.com, magnus.damn@opensource.se, horms@verge.net.au, yoshihiro.shimoda.uh@renesas.com, cm-hiep@jinso.co.jp To: David Miller Return-path: Received: from mail-la0-f53.google.com ([209.85.215.53]:63978 "EHLO mail-la0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753196AbaFBUzg (ORCPT ); Mon, 2 Jun 2014 16:55:36 -0400 Received: by mail-la0-f53.google.com with SMTP id ty20so2949248lab.12 for ; Mon, 02 Jun 2014 13:55:35 -0700 (PDT) In-Reply-To: <20140602.134915.1162774321657125992.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On 06/03/2014 12:49 AM, David Miller wrote: >> Looks like the early SH2/3 SoCs didn't implement the whole register. >> Despite that, sh_eth_dev_init() always writes to this register... :-/ >> So far, the RMCR.RNC bit was mostly set for the Gigabit-capable >> controllers, however that rule wasn't strictly followed. Well, this >> driver is still a mess, and it's hard to deal with it without the >> necessary documentation. > Why don't we therefore: > 1) Skip the register write if the per-chip value is zero. I rather thought about not writing when the register is not implemented. I'll probably look into this when I have time. > 2) Add the RNC bit to all of the gigabit capable controllers. I probably misspoke -- all the Gigabit controllers already have it set, it's just that some 100 MBbps ones have it set, but most don't. WBR, Sergei