Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753356AbZIPNrm (ORCPT ); Wed, 16 Sep 2009 09:47:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752528AbZIPNrl (ORCPT ); Wed, 16 Sep 2009 09:47:41 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:56581 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752460AbZIPNrk (ORCPT ); Wed, 16 Sep 2009 09:47:40 -0400 Date: Wed, 16 Sep 2009 14:47:21 +0100 From: Russell King - ARM Linux To: Krzysztof Halasa Cc: Steve Chen , Felipe Contreras , Jamie Lokier , linux-kernel@vger.kernel.org, Marek Vasut , Pavel Machek , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] arm: remove unused code in delay.S Message-ID: <20090916134721.GA11218@n2100.arm.linux.org.uk> References: <1252875960-21512-1-git-send-email-felipe.contreras@gmail.com> <20090915103739.GA19519@elf.ucw.cz> <1253017761.3273.117.camel@linux-1lbu> <200909151541.08852.marek.vasut@gmail.com> <1253032210.3273.128.camel@linux-1lbu> <94a0d4530909151158y489a96e3x63ff932c713822b0@mail.gmail.com> <1253043875.3273.131.camel@linux-1lbu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1136 Lines: 28 On Tue, Sep 15, 2009 at 11:04:37PM +0200, Krzysztof Halasa wrote: > Steve Chen writes: > > > +config OLD_CPU_DELAY > > + depends on CPU_32v3 || CPU_32v4 || CPU_32v4T > > + bool "Accurate delays" > > + def_bool n > > + help > > + Enable if observing longer than expected delays and need more > > + accuracy. This only applies to older CPUs. > > + > > If it's that simple then why not enable the extra delay code > unconditionally when compiling for those CPUs? Because it's really not that clear cut. Eg, ARM610 and ARM710 work better with it, but StrongARM suffers from delays being too short. Having a kernel configured for all those processors used to be common (since the Acorn RiscPC had pluggable CPU cards, which could be one of those processors.) It's really something that only experienced people should worry about, and not Joe "kernel-builder" Bloggs. -- 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/