From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932741AbaIEN7L (ORCPT ); Fri, 5 Sep 2014 09:59:11 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:44487 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932318AbaIEN7I (ORCPT ); Fri, 5 Sep 2014 09:59:08 -0400 Date: Fri, 5 Sep 2014 14:58:16 +0100 From: Mark Rutland To: Pali =?utf-8?B?Um9ow6Fy?= Cc: Russell King , Ivaylo Dimitrov , Aaro Koskinen , Sebastian Reichel , Will Deacon , "linux-kernel@vger.kernel.org" , Santosh Shilimkar , Pavel Machek , Fabio Estevam , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH] ARM: /proc/cpuinfo: Use DT machine name when possible Message-ID: <20140905135816.GE20164@leverpostej> References: <1403110464-29646-1-git-send-email-pali.rohar@gmail.com> <201409051338.40988@pali> <20140905134542.GD20164@leverpostej> <201409051552.05447@pali> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <201409051552.05447@pali> 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 Fri, Sep 05, 2014 at 02:52:05PM +0100, Pali Rohár wrote: > On Friday 05 September 2014 15:45:42 Mark Rutland wrote: > > On Fri, Sep 05, 2014 at 12:38:40PM +0100, Pali Rohár wrote: > > > On Wednesday 18 June 2014 18:54:24 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. > > > > > > > > Signed-off-by: Pali Rohár > > > > --- > > > > > > > > arch/arm/kernel/setup.c | 7 +++++-- > > > > 1 file changed, 5 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/arch/arm/kernel/setup.c > > > > b/arch/arm/kernel/setup.c index 8a16ee5..fbc7b4f 100644 > > > > --- a/arch/arm/kernel/setup.c > > > > +++ b/arch/arm/kernel/setup.c > > > > @@ -875,10 +875,13 @@ void __init setup_arch(char > > > > **cmdline_p) > > > > > > > > setup_processor(); > > > > mdesc = setup_machine_fdt(__atags_pointer); > > > > > > > > - if (!mdesc) > > > > + if (mdesc) > > > > + machine_name = of_flat_dt_get_machine_name(); > > > > + else > > > > > > > > mdesc = setup_machine_tags(__atags_pointer, > > > > > > > > __machine_arch_type); machine_desc = mdesc; > > > > - machine_name = mdesc->name; > > > > + if (!machine_name) > > > > + machine_name = mdesc->name; > > > > > > > > if (mdesc->reboot_mode != REBOOT_HARD) > > > > > > > > reboot_mode = mdesc->reboot_mode; > > > > > > So, do you really want to break userspace which reading file > > > /proc/cpuinfo (after migration from boardcode --> DT)? > > > > You have no guarantee model name in the DT == the name in a > > board file anyhow, and trying to force that is wrong. So > > further to Russell's reply, I must NAK this from a DT > > perspective. > > > > Realistically your userspace is already broken if relying on > > such things. You built something that only ever worked for a > > particular arbitrary string. So it was already broken for > > every other board, and there was never any guarantee that new > > boards where your userspace could have worked would share the > > same name. > > > > You're trying to fix the wrong side of the equation. > > > > Mark. > > So what is your suggestion for identifing board (name/type) which > will work with any kernel (and will not be broken again by kernel > later)? Without knowing your use case I have no idea if that's even a sane thing to do. Mark. From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Fri, 5 Sep 2014 14:58:16 +0100 Subject: [PATCH] ARM: /proc/cpuinfo: Use DT machine name when possible In-Reply-To: <201409051552.05447@pali> References: <1403110464-29646-1-git-send-email-pali.rohar@gmail.com> <201409051338.40988@pali> <20140905134542.GD20164@leverpostej> <201409051552.05447@pali> Message-ID: <20140905135816.GE20164@leverpostej> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Sep 05, 2014 at 02:52:05PM +0100, Pali Roh?r wrote: > On Friday 05 September 2014 15:45:42 Mark Rutland wrote: > > On Fri, Sep 05, 2014 at 12:38:40PM +0100, Pali Roh?r wrote: > > > On Wednesday 18 June 2014 18:54:24 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. > > > > > > > > Signed-off-by: Pali Roh?r > > > > --- > > > > > > > > arch/arm/kernel/setup.c | 7 +++++-- > > > > 1 file changed, 5 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/arch/arm/kernel/setup.c > > > > b/arch/arm/kernel/setup.c index 8a16ee5..fbc7b4f 100644 > > > > --- a/arch/arm/kernel/setup.c > > > > +++ b/arch/arm/kernel/setup.c > > > > @@ -875,10 +875,13 @@ void __init setup_arch(char > > > > **cmdline_p) > > > > > > > > setup_processor(); > > > > mdesc = setup_machine_fdt(__atags_pointer); > > > > > > > > - if (!mdesc) > > > > + if (mdesc) > > > > + machine_name = of_flat_dt_get_machine_name(); > > > > + else > > > > > > > > mdesc = setup_machine_tags(__atags_pointer, > > > > > > > > __machine_arch_type); machine_desc = mdesc; > > > > - machine_name = mdesc->name; > > > > + if (!machine_name) > > > > + machine_name = mdesc->name; > > > > > > > > if (mdesc->reboot_mode != REBOOT_HARD) > > > > > > > > reboot_mode = mdesc->reboot_mode; > > > > > > So, do you really want to break userspace which reading file > > > /proc/cpuinfo (after migration from boardcode --> DT)? > > > > You have no guarantee model name in the DT == the name in a > > board file anyhow, and trying to force that is wrong. So > > further to Russell's reply, I must NAK this from a DT > > perspective. > > > > Realistically your userspace is already broken if relying on > > such things. You built something that only ever worked for a > > particular arbitrary string. So it was already broken for > > every other board, and there was never any guarantee that new > > boards where your userspace could have worked would share the > > same name. > > > > You're trying to fix the wrong side of the equation. > > > > Mark. > > So what is your suggestion for identifing board (name/type) which > will work with any kernel (and will not be broken again by kernel > later)? Without knowing your use case I have no idea if that's even a sane thing to do. Mark.