From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stas Sergeev Subject: Re: [PATCH 4/6] of: add API for changing parameters of fixed link Date: Fri, 27 Mar 2015 20:31:23 +0300 Message-ID: <551593EB.9060802@list.ru> References: <55155AFC.4050800@list.ru> <55155D35.1070703@list.ru> <5515803F.3020600@list.ru> <551587D1.5070408@list.ru> <5515904A.1060600@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <5515904A.1060600@gmail.com> Sender: netdev-owner@vger.kernel.org To: Florian Fainelli Cc: netdev , Linux kernel , Stas Sergeev , Grant Likely , Rob Herring , "devicetree@vger.kernel.org" , Thomas Petazzoni , Andrew Lunn List-Id: devicetree@vger.kernel.org 27.03.2015 20:15, Florian Fainelli =D0=BF=D0=B8=D1=88=D0=B5=D1=82: > On 27/03/15 09:39, Stas Sergeev wrote: >> 27.03.2015 19:21, Florian Fainelli =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >>>> Do you want mvneta to register a similar callback in of_mdio, inst= ead >>>> of adding an explicit state-updating functions? Something like >>>> of_phy_fixed_link_set_update_callback()? >>> You don't need an of_phy_fixed_link_set_update callback, you just n= eed >>> to provide a fixed_link_update callback in mvneta, that you registe= r, >> That approach I in fact considered initially, as the simplest one, >> and even had a patch. But I disliked the fact that then mvneta will >> exploit the knowledge of the fact that of_phy_register_fixed_link() >> uses a fixed_phy driver. What if the implementation will later chang= e? >=20 > There is no reason why it should change later, that's the entire purp= ose > of why we can tell whether it is a fixed PHY or a regular MDIO-manage= d > PHY, and drivers rely on that for their operations. I don't think anything is exported to the outside of of_mdio. It uses fixed_phy driver completely internally. Assuming that we can pass the created phy_device to the fixed_phy API directly, look like a bit of layering violation to me. But it is not that big as to worry about. :) I don't think many drivers rely on that - perhaps only dsa_slave. So I'll add the second one. > Ok, you could either make of_phy_register_fixed_link() return a > phy_device, OK, if you think that's right - I'll do. I was under an impression that this was intentional to not return the phy. > I think your concerns are valid, but I don't think there is going to = be > any problem with the approach I suggested because there is a contract > that the fixed PHYs and regular PHYs need to OK, so I'll do that on Monday then.