Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759941AbZIPUVZ (ORCPT ); Wed, 16 Sep 2009 16:21:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754580AbZIPUVT (ORCPT ); Wed, 16 Sep 2009 16:21:19 -0400 Received: from h155.mvista.com ([63.81.120.155]:49710 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1754400AbZIPUVT (ORCPT ); Wed, 16 Sep 2009 16:21:19 -0400 Message-ID: <4AB148B7.90306@ru.mvista.com> Date: Thu, 17 Sep 2009 00:21:11 +0400 From: Sergei Shtylyov User-Agent: Thunderbird 2.0.0.23 (Windows/20090812) MIME-Version: 1.0 To: Steve Chen Cc: Krzysztof Halasa , Russell King - ARM Linux , 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 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> <1253053609.3273.139.camel@linux-1lbu> <1253089566.3273.152.camel@linux-1lbu> <1253112555.3273.164.camel@linux-1lbu> In-Reply-To: <1253112555.3273.164.camel@linux-1lbu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1871 Lines: 61 Hello. Steve Chen wrote: >>> +config OLD_CPU_DELAY >>> + depends on CPU_32v3 || CPU_32v4 || CPU_32v4T >>> + bool "Accurate delays for some older CPUs" >>> + def_bool n >>> + help >>> + Try enable this if observing longer than expected delays and need >>> + more accuracy. May cause instability in some CPUs. >>> + >>> >> There is still this uncertain "accurate" in the text. Why don't just >> >> + bool "Different delay() code for some older CPUs" >> > > Sounds good. I also update text under help to better quantify > "accuracy". Updated patch below. Separately, as Russel pointed out, > this should only be done by experienced people, so we even bother with > this patch since the only people should touch this are the people who > knows all the details. > > Document #if 0 code block in delay.S and make it selectable for compile. > > Signed-off-by: Steve Chen > > --- > > arch/arm/Kconfig | 8 ++++++++ > arch/arm/lib/delay.S | 2 +- > 2 files changed, 9 insertions(+), 1 deletions(-) > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index aef63c8..ca8d535 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -813,6 +813,14 @@ config ARM_ERRATA_460075 > ACTLR register. Note that setting specific bits in the ACTLR > register > may not be available in non-secure mode. > > +config OLD_CPU_DELAY > + depends on CPU_32v3 || CPU_32v4 || CPU_32v4T > + bool "Different delay() code for some older CPUs" > + def_bool n > + help > + Try enable this if observing longer than expected delays. This code > Only "enabling"... ;-) WBR, Sergei -- 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/