From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755511AbaIWLDU (ORCPT ); Tue, 23 Sep 2014 07:03:20 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:52421 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753689AbaIWLDT (ORCPT ); Tue, 23 Sep 2014 07:03:19 -0400 Message-ID: <5421536D.4050601@ti.com> Date: Tue, 23 Sep 2014 16:33:09 +0530 From: Kishon Vijay Abraham I User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.0 MIME-Version: 1.0 To: Heikki Krogerus CC: Greg Kroah-Hartman , Felipe Balbi , Vivek Gautam , , Subject: Re: [PATCH 2/6] phy: improved lookup method References: <1408620803-10464-1-git-send-email-heikki.krogerus@linux.intel.com> <1408620803-10464-3-git-send-email-heikki.krogerus@linux.intel.com> <5411C0B2.3060505@ti.com> <20140912140720.GC30816@xps8300> <54130729.5010206@ti.com> <20140915123508.GA16653@xps8300> <20140918102505.GB8567@xps8300> <54200A13.6050201@ti.com> <20140923105311.GB18814@xps8300> In-Reply-To: <20140923105311.GB18814@xps8300> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Tuesday 23 September 2014 04:23 PM, Heikki Krogerus wrote: > On Mon, Sep 22, 2014 at 05:07:55PM +0530, Kishon Vijay Abraham I wrote: >> On Thursday 18 September 2014 03:55 PM, Heikki Krogerus wrote: >>> On Mon, Sep 15, 2014 at 03:35:08PM +0300, Heikki Krogerus wrote: >>>> On Fri, Sep 12, 2014 at 08:16:01PM +0530, Kishon Vijay Abraham I wrote: >>>>> Assume you have 2 phys in your system.. >>>>> static struct phy_lookup usb_lookup = { >>>>> .phy_name = "phy-usb.0", >>>>> .dev_id = "usb.0", >>>>> .con_id = "usb", >>>>> }; >>>>> >>>>> static struct phy_lookup sata_lookup = { >>>>> .phy_name = "sata-usb.1", >>>>> .dev_id = "sata.0", >>>>> .con_id = "sata", >>>>> }; >>>>> >>>>> First you do modprobe phy-usb, the probe of USB PHY driver gets invoked and it >>>>> creates the PHY. The phy-core will find a free id (now it will be 0) and then >>>>> name the phy as phy-usb.0. >>>>> Then with modprobe phy-sata, the phy-core will create phy-sata.1. >>>>> >>>>> This is an ideal case where the .phy_name in phy_lookup matches. >>>>> >>>>> Consider if the order is flipped and the user does modprobe phy-sata first. The >>>>> phy_names won't match anymore (the sata phy device name would be "sata-usb.0"). >>> >>> Actually, I don't think there would be this problem if we used the >>> name of the actual device which is the parent of phy devices, right? >> >> hmm.. but if the parent is a multi-phy phy provider (like pipe3 PHY driver), we >> might end up with the same problem. > > I'm not completely sure what you mean? If you are talking about > platforms with multiple instances of a single phy, I don't see how > there could ever be a scenario where we did not know the order in > which they were enumerated. Can you give an example again? If a single IP implements multiple PHYs (phy-miphy365x.c in linux-phy next), the parent for all the phy devices would be the same. Thanks Kishon