Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753487AbbGQUDX (ORCPT ); Fri, 17 Jul 2015 16:03:23 -0400 Received: from smtp52.i.mail.ru ([94.100.177.112]:36906 "EHLO smtp52.i.mail.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752189AbbGQUDV (ORCPT ); Fri, 17 Jul 2015 16:03:21 -0400 Subject: Re: [PATCH 1/3] fixed_phy: handle link-down case To: Florian Fainelli , netdev References: <55A7C45F.1070501@list.ru> <55A7C49E.2020803@list.ru> <55A83D86.2030505@gmail.com> <55A8E64A.3040009@list.ru> <55A94E5A.9010104@gmail.com> Cc: Linux kernel , Sebastien Rannou , Arnaud Ebalard , Stas Sergeev From: Stas Sergeev Message-ID: <55A95F83.8010900@list.ru> Date: Fri, 17 Jul 2015 23:03:15 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.0.1 MIME-Version: 1.0 In-Reply-To: <55A94E5A.9010104@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Mras: Ok Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2832 Lines: 59 17.07.2015 21:50, Florian Fainelli пишет: > 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 Aren't you missing the fact that .link=0? I think what you say is true only for the link-up case, no? .speed==0 is valid for link-down IMHO: no link - zero speed. > 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 Do you mean this?: core_writel(priv, reg, CORE_STS_OVERRIDE_GMIIP_PORT(port)); Maybe just moving the HW initialization bits to some init func will be a quick fix? > 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 No, it does not. All it does is to allow no speed _when link is down_, which is IMHO a very logical fix. The speed checks for the link-up case are all still there. > - we update the use of the fixed PHY link_update in drivers using it IMHO just 2 drivers: bcmii.c and bcm_sf2.c, and the change is likely trivial, although of course I am not sure in details. > and > convert them to use fixed_phy_update_state instead, which can take some > time and effort to convert Maybe just move the initialization bits out of the link_update callback, but still use the callback for now? Should be simple, no? -- 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/