Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753511AbbGQSv5 (ORCPT ); Fri, 17 Jul 2015 14:51:57 -0400 Received: from mail-pd0-f179.google.com ([209.85.192.179]:34129 "EHLO mail-pd0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751893AbbGQSvz (ORCPT ); Fri, 17 Jul 2015 14:51:55 -0400 Message-ID: <55A94E5A.9010104@gmail.com> Date: Fri, 17 Jul 2015 11:50:02 -0700 From: Florian Fainelli User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Stas Sergeev , netdev CC: Linux kernel , Sebastien Rannou , Arnaud Ebalard , Stas Sergeev Subject: Re: [PATCH 1/3] fixed_phy: handle link-down case References: <55A7C45F.1070501@list.ru> <55A7C49E.2020803@list.ru> <55A83D86.2030505@gmail.com> <55A8E64A.3040009@list.ru> In-Reply-To: <55A8E64A.3040009@list.ru> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2356 Lines: 56 On 17/07/15 04:26, Stas Sergeev wrote: > 17.07.2015 02:25, Florian Fainelli пишет: >> On 16/07/15 07:50, Stas Sergeev wrote: >>> >>> Currently fixed_phy driver recognizes only the link-up state. >>> This simple patch adds an implementation of link-down state. >>> It fixes the status registers when link is down, and also allows >>> to register the fixed-phy with link down without specifying the speed. >> >> This patch still breaks my setups here, e.g: drivers/net/dsa/bcm_sf2.c, >> but I will look into it. >> >> Do we really need this for now for your two other patches to work >> properly, or is it just nicer to have? > Yes, absolutely. > Otherwise registering fixed phy will return -EINVAL > because of the missing link speed (even though the link > is down). Ok, I see the problem that you have now. Arguably you could say that according to the fixed-link binding, speed needs to be specified and the code correctly errors out with such an error if you do not specify it. I also agree that having to specify speed and duplex for something you will end-up auto-negotiating has no useful purpose. > > Please, see what makes a problem. I can't reproduce what you report. > So is different is that I use a link_update callback, and so we rely on at least one call of this function to initialize the hardware in drivers/net/dsa/bcm_sf2.c for this to work, after that, the hardware reflects the fixed link parameters we configured, and we feed the fixed_phy_status information from the hardware directly. >From there I see two different ways to fix this: - we ignore the fixed_phy_update_regs return value in fixed_phy_add(), but that will make us avoid doing verification on the speed, which is not so great, but is essentially what your patch does anyway - we update the use of the fixed PHY link_update in drivers using it and convert them to use fixed_phy_update_state instead, which can take some time and effort to convert What do you think? I would go with option 1 and eventually introduce a special switch() case on the speed settings just to validate we know them. Thanks -- Florian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/