From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755194AbaGKTbr (ORCPT ); Fri, 11 Jul 2014 15:31:47 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:38123 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752043AbaGKTbq (ORCPT ); Fri, 11 Jul 2014 15:31:46 -0400 Date: Fri, 11 Jul 2014 21:31:44 +0200 From: Pavel Machek To: Russell King - ARM Linux Cc: Pali =?iso-8859-1?Q?Roh=E1r?= , Santosh Shilimkar , Will Deacon , Ivaylo Dimitrov , Sebastian Reichel , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ARM: /proc/cpuinfo: Use DT machine name when possible Message-ID: <20140711193144.GC20015@amd.pavel.ucw.cz> References: <1403110464-29646-1-git-send-email-pali.rohar@gmail.com> <20140618190108.GI32514@n2100.arm.linux.org.uk> <201406182109.59059@pali> <20140618195908.GJ32514@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20140618195908.GJ32514@n2100.arm.linux.org.uk> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 2014-06-18 20:59:08, Russell King - ARM Linux wrote: > On Wed, Jun 18, 2014 at 09:09:58PM +0200, Pali Rohár wrote: > > On Wednesday 18 June 2014 21:01:09 Russell King - ARM Linux > > wrote: > > > On Wed, Jun 18, 2014 at 06:54:24PM +0200, 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. > > > > > > http://archive.arm.linux.org.uk/lurker/message/20130726.132850 > > > .53d47576.en.html > > > > > > "If userspace wants to get at the DT information about a > > > platform, we already have ways that can happen already - we > > > export the DT stuff so that kexec's tools can get at it." > > > > Userspace application does not know that kernel using DT. And > > also it does not want to get DT information. Only board/machine > > name. So existing applications stop working after migration to > > DT. And because legacy board boot code (without DT) is going to > > be removed for ARM in near future this will permanently break > > existing applications. > > We're already breaking the userspace API through moving to DT, because > all the device names in /sys/devices are changing. Userspace is going > to have to cope with change as we move towards DT. This is just > another aspect of moving towards DT, and one which userspace is going > to have to deal with. You don't _have_ to break /proc/cpuinfo. No, "DT breaks stuff" should not be reason to "break more stuff". (Actually, I'm not aware of anything DT would have to break.) Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: pavel@ucw.cz (Pavel Machek) Date: Fri, 11 Jul 2014 21:31:44 +0200 Subject: [PATCH] ARM: /proc/cpuinfo: Use DT machine name when possible In-Reply-To: <20140618195908.GJ32514@n2100.arm.linux.org.uk> References: <1403110464-29646-1-git-send-email-pali.rohar@gmail.com> <20140618190108.GI32514@n2100.arm.linux.org.uk> <201406182109.59059@pali> <20140618195908.GJ32514@n2100.arm.linux.org.uk> Message-ID: <20140711193144.GC20015@amd.pavel.ucw.cz> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed 2014-06-18 20:59:08, Russell King - ARM Linux wrote: > On Wed, Jun 18, 2014 at 09:09:58PM +0200, Pali Roh?r wrote: > > On Wednesday 18 June 2014 21:01:09 Russell King - ARM Linux > > wrote: > > > On Wed, Jun 18, 2014 at 06:54:24PM +0200, Pali Roh?r 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. > > > > > > http://archive.arm.linux.org.uk/lurker/message/20130726.132850 > > > .53d47576.en.html > > > > > > "If userspace wants to get at the DT information about a > > > platform, we already have ways that can happen already - we > > > export the DT stuff so that kexec's tools can get at it." > > > > Userspace application does not know that kernel using DT. And > > also it does not want to get DT information. Only board/machine > > name. So existing applications stop working after migration to > > DT. And because legacy board boot code (without DT) is going to > > be removed for ARM in near future this will permanently break > > existing applications. > > We're already breaking the userspace API through moving to DT, because > all the device names in /sys/devices are changing. Userspace is going > to have to cope with change as we move towards DT. This is just > another aspect of moving towards DT, and one which userspace is going > to have to deal with. You don't _have_ to break /proc/cpuinfo. No, "DT breaks stuff" should not be reason to "break more stuff". (Actually, I'm not aware of anything DT would have to break.) Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html