From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AFDABC43331 for ; Tue, 31 Mar 2020 23:01:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8890020842 for ; Tue, 31 Mar 2020 23:01:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731473AbgCaXBy (ORCPT ); Tue, 31 Mar 2020 19:01:54 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:33784 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730589AbgCaXBy (ORCPT ); Tue, 31 Mar 2020 19:01:54 -0400 Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jJPtG-00016q-8p; Wed, 01 Apr 2020 01:01:50 +0200 Received: by nanos.tec.linutronix.de (Postfix, from userid 1000) id BE3C5103A01; Wed, 1 Apr 2020 01:01:49 +0200 (CEST) From: Thomas Gleixner To: Thierry Reding Cc: John Stultz , Stephen Boyd , linux-kernel@vger.kernel.org Subject: Re: [PATCH] clocksource: Add debugfs support In-Reply-To: <20200331222917.GG2954599@ulmo> References: <20200331214045.2957710-1-thierry.reding@gmail.com> <87lfnguqky.fsf@nanos.tec.linutronix.de> <20200331222917.GG2954599@ulmo> Date: Wed, 01 Apr 2020 01:01:49 +0200 Message-ID: <87d08suo0y.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thierry Reding writes: > On Wed, Apr 01, 2020 at 12:06:37AM +0200, Thomas Gleixner wrote: >> It does not provide any information about the clocksource, it provides >> an interface to read the counter - nothing else. > > The counter is part of the information about a clocksource, isn't it? Sorry to be pedantic, but no. Information about a clocksource is the name, the type, the frequency, bitwidth etc. The counter file is not providing information about the clocksource. It's exposing an accessor to the clocksource itself. > I can also add some information about what I intend to use this for, > though it'll be a bit boring because I really only want this as a way > of testing that I'm reading from the right registers and that these > counters are running. A debugfs interface seemed like a better and more > widely useful way to achieve that than implementing some one-off hack to > poll those registers. But how much value has this interface beyond the 'hack a driver for a new clocksource' experience? To me none, but that might be my personal skewed view. Thanks, tglx