Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753406AbaGJPf6 (ORCPT ); Thu, 10 Jul 2014 11:35:58 -0400 Received: from mail-ob0-f174.google.com ([209.85.214.174]:49668 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751019AbaGJPf4 (ORCPT ); Thu, 10 Jul 2014 11:35:56 -0400 MIME-Version: 1.0 In-Reply-To: <20140710110720.03f437eb@bbrezillon> References: <1403777615-25685-1-git-send-email-boris.brezillon@free-electrons.com> <1403777615-25685-2-git-send-email-boris.brezillon@free-electrons.com> <53AC7BFD.2070806@free-electrons.com> <53AD22D8.2090301@atmel.com> <20140710110720.03f437eb@bbrezillon> From: Florian Fainelli Date: Thu, 10 Jul 2014 08:35:15 -0700 Message-ID: Subject: Re: [PATCH v2 1/2] ARM: at91/dt: describe rgmii ethernet phy connected to sama5d3xek boards To: Boris BREZILLON Cc: Nicolas Ferre , Jean-Christophe Plagniol-Villard , Alexandre Belloni , Andrew Victor , netdev , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "David S. Miller" , "Shen, Voice" , "devicetree@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2014-07-10 2:07 GMT-07:00 Boris BREZILLON : > On Fri, 27 Jun 2014 09:52:56 +0200 > Nicolas Ferre wrote: > >> On 26/06/2014 22:01, Boris BREZILLON : >> > Hi Florian, >> > >> > On 26/06/2014 20:15, Florian Fainelli wrote: >> >> Hi Boris, >> >> >> >> 2014-06-26 3:13 GMT-07:00 Boris BREZILLON : >> >>> Add ethernet-phy node and specify phy interrupt (connected to pin PB25). >> >>> >> >>> The PHY address is not specified here because atmel have 2 different >> >>> designs >> >>> for its CPU modules: one is connecting PHYAD[0-2] pins to pull up resistors >> >>> (Embest design) and the other one is connection PHYAD0 to a pull up >> >>> resistor and PHYAD[1-2] to pull down resistors (Ronetix design). >> >>> As a result, Ronetix design will have its PHY available at address 0x1 and >> >>> Embest design at 0x7. >> >>> Let the net PHY core automatically detect the PHY address by scanning the >> >>> MDIO bus. >> >> I though the compatible string was listed as a required property, but >> >> it is not. The 'reg' property however is listed as required, although >> >> the of_miodbus_register() works just fine without it, although that is >> >> a Linux-specific implementation detail. >> > >> > Indeed, it's listed in the required property list of the DT binding doc, >> > but the code implement auto detection if reg is missing. >> > However this line [1] clearly shows that specifying the reg property is >> > the preferred way of doing things. >> > >> > I could define 2 different sama5d3xcm.dtsi (sama5d3xcm-ronetix.dtsi and >> > sama5d3xcm-embest.dtsi) to avoid this dirty hack, >> > but then we would have 2 more dtb and the user would have to determine >> > which CPU module he owns to choose the appropriate dtb. >> > If at91, arm-soc and DT maintainers agree with this approach I can >> > definitely propose something. >> >> Yes Boris, I definitively prefer not to add another .dtsi file for this >> series if we can avoid it. >> > > Okay, now that I don't specify the reg property I have a bunch of > noisy logs (which is exactly what the developer of of_mdio.c wanted in > order to force people to specify the reg property). > > It seems to be a problem for atmel users (all these logs make them > think there is something wrong with the net device). > > Apart from the dts/dtsi split solution, which Nicolas wants to avoid, I > see two solutions here: > > 1) remove the logs (or use dev_dbg instead of dev_info) from of_mdio.c. > But I'm pretty sure this solution won't be accepted :-). I am fine with using dev_dbg() instead of dev_info() for that sort of messages, provided that you state the rationale of this change (spewing the log console with probing messages) and specify tha the 'reg' property is optional. > > 2) define 2 ethernet phys (one for each possible solution). I tested it > and it works fine (only the available PHY is registered and there is no > noisy logs anymore). One advantage of that solution is that you'll get slightly faster boot times since you won't have to auto-probe for the PHYs on the MDIO bus, the time savings get bigger as you start using higher PHY addresses. > > Could net and DT maintainers help us choose the best solution (or > propose a new one) ? > > Best Regards, > > Boris > > -- > Boris Brezillon, Free Electrons > Embedded Linux and Kernel engineering > http://free-electrons.com -- 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/