From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753197AbbKQNIb (ORCPT ); Tue, 17 Nov 2015 08:08:31 -0500 Received: from unicorn.mansr.com ([81.2.72.234]:44354 "EHLO unicorn.mansr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752290AbbKQNI3 convert rfc822-to-8bit (ORCPT ); Tue, 17 Nov 2015 08:08:29 -0500 From: =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?= To: Marc Gonzalez Cc: Daniel Lezcano , Thomas Gleixner , LKML , Linux ARM , Arnd Bergmann , Russell King Subject: Re: [PATCH] clocksource/drivers/tango-xtal: Replace code by clocksource_mmio_init References: <1447412292-841-1-git-send-email-daniel.lezcano@linaro.org> <5645D5A0.1000502@sigmadesigns.com> <564B1C1C.7070801@linaro.org> <564B222E.5080209@sigmadesigns.com> Date: Tue, 17 Nov 2015 13:08:20 +0000 In-Reply-To: <564B222E.5080209@sigmadesigns.com> (Marc Gonzalez's message of "Tue, 17 Nov 2015 13:48:46 +0100") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Marc Gonzalez writes: > On 17/11/2015 13:22, Daniel Lezcano wrote: >> On 11/13/2015 01:20 PM, Marc Gonzalez wrote: >>> On 13/11/2015 11:58, Daniel Lezcano wrote: >>> >>>> The current code to initialize, register and read the clocksource is >>>> already factored out in mmio.c via the clocksource_mmio_init function. >>>> >>>> Factor out the code with the clocksource_mmio_init function. >>> >>> The reason I didn't like clocksource_mmio_init() is because it exports >>> 4 generic accessors. >>> >>> I guess this function makes more sense when all platforms are using it, >>> in an ARCH_MULTIPLATFORM kernel. (Also the accessors are probably quite >>> small, so the waste is probably minimal.) >> >> Hi Marc, >> >> it is not clear for me if you agree with this patch or not. Can you >> clarify ? > > [ Adding rmk as the original mmio.c author ] > > Hello Daniel, > > It's hard to give a straight answer. From my limited perspective (building > a kernel for Sigma boards only) I feel that mmio.c brings nothing. (As you > mentioned, it would be interesting to measure whether having reg_base in > the ctx, rather than as a global is better or worse for perf, though the > actual difference may be lost in the noise.) > > On the other hand, I can see how a different perspective, such as yours, > may see benefits in having all drivers use the same APIs; and there may > be other savings for ARCH_MULTIPLATFORM builds with lots of platforms. I think the patch is good. If there are issues with clocksource_mmio those should addressed separately. -- Måns Rullgård mans@mansr.com