Received: by 2002:a25:ca44:0:0:0:0:0 with SMTP id a65csp592810ybg; Tue, 28 Jul 2020 13:42:29 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwu0pwviiHeyp2BYNb+PNW/qWQnsu+8745oRHaz2zb2zIJqPcFQC4seBto7f/dcGveWn7Ws X-Received: by 2002:a17:906:ce32:: with SMTP id sd18mr27782394ejb.228.1595968949560; Tue, 28 Jul 2020 13:42:29 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1595968949; cv=none; d=google.com; s=arc-20160816; b=Ijdbhhxw0Yf6ftq+qo3uj4ZNYW6oPdNAEOsaNqgiR648xVl/LiCIBtOWOBnn25HMyc hRvpQuoypokzQxKDayRzo9XHGUumx8/0N02vX+5wIPeUPaNqLigOrQ/uU48P/dPudJIQ eH3PKh/Kob16N2vmTPNwcq2GRt56DolJaRatZv/6vn4H44vkLFe3Ix2U2TfM5sLkZPSh iLzMBNq/qu8bmb0AbGk2lUov4YBS+BKs6jc3/s5pGPX52JG6U4qG4CZOcNgNozg7TJw1 gXSLT4XUpiU+1vE/kanHOq0253j65sMiJa0avRu4BRVwASVOpsk/DCXtBd9JRpmYfD2m Yk0g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=tkiskrPGYpAz2A9zc7xjy6y7k/mEqWrnX7uC1GEsF1U=; b=P4Feiq1/JS2CY+3C0gU5XO9stbFZX6Zd8OD0cEu4YO99H77f9NFO5wgBo+MjNOtVXA qHC/HWkW+EHs2JEpAIIawKcdhQ2ymB1GJcyyiwUUgBCHhqqIWcgd5xl+T9CtA/ax8O3F bD0EF8EIUwkagSWkWjfyWz13Rt52ToxZcq4YibdCFhubf0TcgpUEPKTiFzqDKIljhMeA dohiYeTUhlQ5tUK6pO/mbZODxFQG0teYQGnaJUg8Ix6TQtSLwm/HSZ1C28Ym+dYbXUHb ikyDv7NcQgcyfKRXsxhslnPR84x5Ql/yZ+EiHCQkxv/qGW+wsO/2d5R8WD4nUiP6/7rc GAbg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id dn20si12016972ejc.341.2020.07.28.13.42.08; Tue, 28 Jul 2020 13:42:29 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729214AbgG1UlC (ORCPT + 99 others); Tue, 28 Jul 2020 16:41:02 -0400 Received: from jabberwock.ucw.cz ([46.255.230.98]:50106 "EHLO jabberwock.ucw.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728828AbgG1UlB (ORCPT ); Tue, 28 Jul 2020 16:41:01 -0400 Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 266ED1C0BEB; Tue, 28 Jul 2020 22:41:00 +0200 (CEST) Date: Tue, 28 Jul 2020 22:40:59 +0200 From: Pavel Machek To: Sumeet Pawnikar Cc: rjw@rjwysocki.net, rui.zhang@intel.com, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, andriy.shevchenko@intel.com, srinivas.pandruvada@linux.intel.com Subject: Re: [PATCH v2] powercap: Add Power Limit4 support Message-ID: <20200728204059.GF1012@bug> References: <1594715306-10411-1-git-send-email-sumeet.r.pawnikar@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1594715306-10411-1-git-send-email-sumeet.r.pawnikar@intel.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! > Modern Intel Mobile platforms support power limit4 (PL4), which is > the SoC package level maximum power limit (in Watts). It can be used > to preemptively limits potential SoC power to prevent power spikes > from tripping the power adapter and battery over-current protection. > This patch enables this feature by exposing package level peak power > capping control to userspace via RAPL sysfs interface. With this, > application like DTPF can modify PL4 power limit, the similar way > of other package power limit (PL1). > As this feature is not tested on previous generations, here it is > enabled only for the platform that has been verified to work, > for safety concerns. So what happens when the user sets this too high? Battery on fire? Or just sudden poweroff? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html