Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752483AbaLDAdb (ORCPT ); Wed, 3 Dec 2014 19:33:31 -0500 Received: from mail-wg0-f53.google.com ([74.125.82.53]:42215 "EHLO mail-wg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751106AbaLDAda convert rfc822-to-8bit (ORCPT ); Wed, 3 Dec 2014 19:33:30 -0500 MIME-Version: 1.0 In-Reply-To: <201411242319.27481@pali> References: <1403110464-29646-1-git-send-email-pali.rohar@gmail.com> <201406182122.29623@pali> <201411242319.27481@pali> From: Rob Herring Date: Wed, 3 Dec 2014 18:33:08 -0600 Message-ID: Subject: Re: [PATCH] ARM: /proc/cpuinfo: Use DT machine name when possible To: =?UTF-8?Q?Pali_Roh=C3=A1r?= Cc: Russell King , Santosh Shilimkar , Will Deacon , Ivaylo Dimitrov , Sebastian Reichel , Pavel Machek , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 24, 2014 at 4:19 PM, Pali Rohár wrote: > On Wednesday 18 June 2014 22:46:19 Rob Herring wrote: >> On Wed, Jun 18, 2014 at 2:22 PM, Pali Rohár > wrote: >> > On Wednesday 18 June 2014 21:07:35 Rob Herring wrote: >> >> On Wed, Jun 18, 2014 at 11:54 AM, Pali Rohár >> > >> > wrote: >> >> > Machine name from board description is some generic name >> >> > on DT kernel. DT provides machine name property which is >> >> > specific for board, so use it instead generic one when >> >> > possible. >> >> > [...] >> > Basically in DT kernel is missing Hardware, Revision and >> > probably also Serial key. (Now I used only qemu for testing >> > which set serial key to 0). All these informations is used >> > by userspace applications which determinate how to behave. >> >> It is somewhat fragile to expect the name in the DT to match >> the old name from the kernel. As your patch to n900 dts >> shows, we'd probably have to update every dts file to make >> them match. While I think we should work to remove this >> string from the kernel, userspace depending on the DT model >> string is a bad idea. For example, if you had some platform >> with multiple OEMs just rebranding the same base design, they >> may all want to put their own model string into each product. >> The true h/w id is the compatible string. >> >> Serial number is easy. There is already a standard although >> not widely used property for it with "/serial-number". You >> just need to wire it up to cpuinfo. >> > > There is no "/serial-number" property in kernel: > > $ ls -l -a /sys/bus/soc/devices/soc0/ > drwxr-xr-x 3 0 0 0 Jan 1 00:00 . > drwxr-xr-x 18 0 0 0 Jan 1 00:00 .. > -r--r--r-- 1 0 0 4096 Jan 1 00:00 family > -r--r--r-- 1 0 0 4096 Jan 1 00:00 machine > drwxr-xr-x 2 0 0 0 Jan 1 00:00 power > -r--r--r-- 1 0 0 4096 Jan 1 00:00 revision > lrwxrwxrwx 1 0 0 0 Jan 1 00:00 > subsystem -> ../../bus/soc > -r--r--r-- 1 0 0 4096 Jan 1 00:00 type > -rw-r--r-- 1 0 0 4096 Jan 1 00:00 uevent Wrong place. If you put /serial-number in your DT, then it will be in /proc/device-tree/serial-number. If you want to wire that up to /proc/cpuinfo, I would be fine with that. Rob -- 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/