From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760704AbZEANaV (ORCPT ); Fri, 1 May 2009 09:30:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761834AbZEAN3I (ORCPT ); Fri, 1 May 2009 09:29:08 -0400 Received: from moutng.kundenserver.de ([212.227.126.177]:51992 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761823AbZEAN3G (ORCPT ); Fri, 1 May 2009 09:29:06 -0400 From: Arnd Bergmann To: Alan Cox Subject: Re: [PATCH 04/27] asm-generic: add legacy I/O header files Date: Fri, 1 May 2009 15:29:04 +0200 User-Agent: KMail/1.9.9 Cc: Russell King , Michal Simek , linux-arch@vger.kernel.org, Remis Lima Baima , linux-kernel@vger.kernel.org References: <20090501123728.GC27799@flint.arm.linux.org.uk> <20090501140904.69f44406@lxorguk.ukuu.org.uk> In-Reply-To: <20090501140904.69f44406@lxorguk.ukuu.org.uk> X-Face: I@=L^?./?$U,EK.)V[4*>`zSqm0>65YtkOe>TFD'!aw?7OVv#~5xd\s,[~w]-J!)|%=]>=?utf-8?q?+=0A=09=7EohchhkRGW=3F=7C6=5FqTmkd=5Ft=3FLZC=23Q-=60=2E=60Y=2Ea=5E?= =?utf-8?q?3zb?=) =?utf-8?q?+U-JVN=5DWT=25cw=23=5BYo0=267C=26bL12wWGlZi=0A=09=7EJ=3B=5Cwg?= =?utf-8?q?=3B3zRnz?=,J"CT_)=\H'1/{?SR7GDu?WIopm.HaBG=QYj"NZD_[zrM\Gip^U MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200905011529.04774.arnd@arndb.de> X-Provags-ID: V01U2FsdGVkX1/EU/7gEO5O0ncrZYsnAvm84bbJDoUxfOQaB3Z eT3nFRZuvx/IejzZrwm8jaN/gAts+/N4iAC1pUlGiQ7yAem6MO zVK+nj4a6aOdUoSKBMY2A== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 01 May 2009, Alan Cox wrote: > Joining in late but its not at all highly PC specific. The same frequency > is used for a whole pile of setups (Alpha etc). It's not well named but > there are good sound reasons the PC chose 1193182 and while those reasons > have long lapsed its a good frequency for other reasons nowdays. > > The clock isn't for the PIC either - its for the PIT (although its used > to clock various other things). > > We actually have a define of PIT_TICK_RATE internal to the x86 port for > those x86 cases that can use it. How about this comment then: /* * CLOCK_TICK_RATE is traditionally the base frequency using the PC-style * i8253 "PIT" timer. Architecture independent device drivers should not * rely on this value. * Any architecture that either has a real PC-style PIT, or does not have a * fixed timer interval at all and just needs to provide some value here * should just fall back to this default. */ Arnd <><