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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 AF3BEECE588 for ; Tue, 15 Oct 2019 17:19:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8176A20854 for ; Tue, 15 Oct 2019 17:19:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="awoHS9eV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730713AbfJORTm (ORCPT ); Tue, 15 Oct 2019 13:19:42 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:45859 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730706AbfJORTl (ORCPT ); Tue, 15 Oct 2019 13:19:41 -0400 Received: by mail-pf1-f196.google.com with SMTP id y72so12878557pfb.12 for ; Tue, 15 Oct 2019 10:19:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=TWtOdLU950qO44gtWRI1EevokHAunCwQ1TaUeaOgpXk=; b=awoHS9eVotcWQ2gbtqYURIscmftRO0hnxBkikpia+e0TsfNOnDMM3fOzVNuX5Ehopo uebssmp/dLs6BBLFKoi04U1jAnQnHV4oiLzvt/DmQZrPeeec1Kw5VWPem+vi+yrWn0ZX gXuxpxVFvn1J4rubjdujIthIBrBKUR2U9szVQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=TWtOdLU950qO44gtWRI1EevokHAunCwQ1TaUeaOgpXk=; b=Shy2rvKICC6AD0DYpUXqEof5aXh2xM4FAwLP3diuuH1xFSitNWdJsFbUJj5gKdLbys 8b+k3/sRp/zsYgA7ie3SFYbsrA/KxrNa3KIvepd6CyUBOdJlyaywPJAYlKXp3rpcOTZV 48ogvWkAkcY10lhkuD273O9+xbUXHjBfkrXq54HQKOGHZXfniesIkXxElz+kTrPSctZX /W1Ue7LXLclBehWhZ5uhAyhcvO5SuZHqBrPQmxK0WC6ZixBasHUkcjp7lLdBQTL+ki/P cWTwg5aTkOwZ8ZMDl12pPDiZJgcUh7KDseSo6vF+SnHAj4cgQocDx7bamGTPNFQes04L ZE+Q== X-Gm-Message-State: APjAAAUi1AdkhAQmH2AYMskoPAw6EAEiqZl+7k2TRu3zLh0l5d11mnTw jFZEGWrRvYO3s1MxaqV4GU1x3Q== X-Google-Smtp-Source: APXvYqwgk66PcBDs4wpLLZVJPG/VI50z6RsUr748jWOgPSQEjjgVW/mRJuA6zAgAaY2oFXrP0Je05g== X-Received: by 2002:aa7:924f:: with SMTP id 15mr40455528pfp.194.1571159981109; Tue, 15 Oct 2019 10:19:41 -0700 (PDT) Received: from localhost ([2620:15c:202:1:4fff:7a6b:a335:8fde]) by smtp.gmail.com with ESMTPSA id s36sm22990237pgk.84.2019.10.15.10.19.39 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 15 Oct 2019 10:19:40 -0700 (PDT) Date: Tue, 15 Oct 2019 10:19:37 -0700 From: Matthias Kaehlcke To: Ulf Hansson Cc: Steven Rostedt , "Rafael J . Wysocki" , Kevin Hilman , Len Brown , Pavel Machek , Greg Kroah-Hartman , Ingo Molnar , Douglas Anderson , Linux PM , Amit Kucheria , Linux Kernel Mailing List Subject: Re: [PATCH v1] PM / Domains: Add tracepoints Message-ID: <20191015171937.GO87296@google.com> References: <20190926150406.v1.1.I07a769ad7b00376777c9815fb169322cde7b9171@changeid> <20190927044239.589e7c4c@oasis.local.home> <20191001163542.GB87296@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Hi Ulf, On Tue, Oct 15, 2019 at 02:37:42PM +0200, Ulf Hansson wrote: > On Tue, 1 Oct 2019 at 18:35, Matthias Kaehlcke wrote: > > > > On Fri, Sep 27, 2019 at 04:42:39AM -0400, Steven Rostedt wrote: > > > On Thu, 26 Sep 2019 15:04:38 -0700 > > > Matthias Kaehlcke wrote: > > > > > > > Define genpd_power_on/off and genpd_set_performance_state > > > > tracepoints and use them. > > > > > > I agree with Greg about adding a "why" you need this. But, in case > > > there's a good reason to have this, I have comments about the code > > > below. > > > > Thanks Greg and Steven for your comments. > > > > How about this instead: > > > > Add tracepoints for genpd_power_on, genpd_power_off and > > genpd_set_performance_state. The tracepoints can help with > > understanding power domain behavior of a given device, which > > may be particularly interesting for battery powered devices > > and suspend/resume. > > Apologize for the delay, no excuse! > > I don't mind adding trace events, as long as it's for good reasons - > and to me, that seems a bit questionable here. > > According to the above, I believe the information you need is already > available via genpd's debugfs interface, no? Not in all cases, e.g. you can't peek at sysfs while the device is suspended. Also sysfs doesn't help much with seeing that a PD is toggling between on an off for some (possibly legitimate) reason. At this point I don't need this information badly, just thought it could be useful. No problem if it is decided to hold back on it for now.