From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755293AbaIWKxR (ORCPT ); Tue, 23 Sep 2014 06:53:17 -0400 Received: from mga09.intel.com ([134.134.136.24]:46634 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753967AbaIWKxQ (ORCPT ); Tue, 23 Sep 2014 06:53:16 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,579,1406617200"; d="scan'208";a="577469684" Date: Tue, 23 Sep 2014 13:53:11 +0300 From: Heikki Krogerus To: Kishon Vijay Abraham I Cc: Greg Kroah-Hartman , Felipe Balbi , Vivek Gautam , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: [PATCH 2/6] phy: improved lookup method Message-ID: <20140923105311.GB18814@xps8300> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54200A13.6050201@ti.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? Thanks, -- heikki