From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757981Ab1DAPum (ORCPT ); Fri, 1 Apr 2011 11:50:42 -0400 Received: from moutng.kundenserver.de ([212.227.126.171]:56292 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752508Ab1DAPuk (ORCPT ); Fri, 1 Apr 2011 11:50:40 -0400 From: Arnd Bergmann To: Detlef Vollmann Subject: Re: [GIT PULL] omap changes for v2.6.39 merge window Date: Fri, 1 Apr 2011 17:50:17 +0200 User-Agent: KMail/1.12.2 (Linux/2.6.37; KDE/4.3.2; x86_64; ; ) Cc: Ingo Molnar , david@lang.hm, "Russell King - ARM Linux" , Nicolas Pitre , Tony Lindgren , Catalin Marinas , lkml , "H. Peter Anvin" , David Brown , linux-omap@vger.kernel.org, Linus Torvalds , Thomas Gleixner , linux-arm-kernel@lists.infradead.org References: <201104011659.40443.arnd@arndb.de> <4D95EF8E.9080902@vollmann.ch> In-Reply-To: <4D95EF8E.9080902@vollmann.ch> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201104011750.17344.arnd@arndb.de> X-Provags-ID: V02:K0:gr9k8EoUyuVVpA1fVkEJMZ1N9CcMrfGd+3TPWEnUDcU gRx1gX38udt8TEGJ65ZHRfD7oPzxLL7Faxxy1oHKSMvJcN8l/L 2zeHgE5wG2shHsRKeigg4VE0B0fWh8KAJN6ATGoIK6qt7fK1Zb wqGlE/HSASzkOvPdZ+Bi+HkOXs2jN7qZhUKgguXd17dCQCsQsq EHbWKRo4CNOYr9kbZhonA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 01 April 2011, Detlef Vollmann wrote: > On 04/01/11 16:59, Arnd Bergmann wrote: > > On Friday 01 April 2011, Detlef Vollmann wrote: > >> On 04/01/11 15:54, Arnd Bergmann wrote: > > > >>> 9. All interesting work is going into a handful of platforms, all of which > >>> are ARMv7 based. > >> Define interesting. > > > > The ones that are causing the churn that we're talking about. > > Platforms that have been working forever and only need to get > > the occasional bug fix are boring, i.e. not the problem. > In the ARM tree I only know mach-at91. > Atmel still introduces new SOCs based on ARM926EJ-S, and that makes > perfect sense for lots of applications. I thought new ones were generally Cortex-M3 based. Either way, even if there are exceptions, focusing on ARMv7 at first should give a good representation of the new development. > >>> 12. Supporting many different boards with a single kernel binary is a > >>> useful goal. > >> Generally not for embedded systems (for me, a mobile PDA/phone is just a > >> small computer with a crappy keyboard, but not an embedded system). > > > > True. For embedded, this would not be an important thing to do, but > > also not hurt. > It costs you flash space. Well, the idea was not to force everyone to enable all options. When this is done right, the kernel would not be any bigger. > >>> * Strictly no crap > >>> * No board files > >> Where do you put code that needs to run very early (e.g. pinging the > >> watchdog)? > > > > Don't know. I'd hope we can get fast enough to the phase where device > > drivers get initialized. > Nope, never happened for me :-( > (Watchdog timeouts are often 1s or less.) 1s is a long time. Most of the boot process is drivers anyway, so we just need to make sure that the watchdog is early enough. > > I believe that rule is generally accepted today, but we don't always > > enforce it. > Without device tree, Kconfig option is the only way that really > works today (no runtime HW detection, and same board ID with different > setups). I believe that has never been an accepted way of doing things, you are supposed to get a new board ID for every new board, hence the name ;-). ARnd