From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: Re: [PATCH 1/3] fixed_phy: handle link-down case Date: Fri, 17 Jul 2015 11:50:02 -0700 Message-ID: <55A94E5A.9010104@gmail.com> References: <55A7C45F.1070501@list.ru> <55A7C49E.2020803@list.ru> <55A83D86.2030505@gmail.com> <55A8E64A.3040009@list.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Linux kernel , Sebastien Rannou , Arnaud Ebalard , Stas Sergeev To: Stas Sergeev , netdev Return-path: In-Reply-To: <55A8E64A.3040009@list.ru> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 17/07/15 04:26, Stas Sergeev wrote: > 17.07.2015 02:25, Florian Fainelli =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >> 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 spe= ed. >> >> This patch still breaks my setups here, e.g: drivers/net/dsa/bcm_sf2= =2Ec, >> 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 th= e 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. >=20 > Please, see what makes a problem. I can't reproduce what you report. >=20 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. =46rom 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 an= d 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 th= em. Thanks --=20 =46lorian