Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753572AbaFWNDD (ORCPT ); Mon, 23 Jun 2014 09:03:03 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:39498 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751066AbaFWNDB (ORCPT ); Mon, 23 Jun 2014 09:03:01 -0400 Date: Mon, 23 Jun 2014 15:02:59 +0200 From: Pavel Machek To: Ilia Mirkin Cc: Greg KH , kernel list , Ben Skeggs , Alexandre Courbot , David Airlie , "dri-devel@lists.freedesktop.org" Subject: Re: unparseable, undocumented /sys/class/drm/.../pstate Message-ID: <20140623130259.GA29809@amd.pavel.ucw.cz> References: <20140621180201.GA4621@amd.pavel.ucw.cz> <20140621194538.GA4903@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun 2014-06-22 22:12:14, Ilia Mirkin wrote: > On Sat, Jun 21, 2014 at 3:45 PM, Greg KH wrote: > > On Sat, Jun 21, 2014 at 02:22:59PM -0400, Ilia Mirkin wrote: > >> On Sat, Jun 21, 2014 at 2:02 PM, Pavel Machek wrote: > >> > Hi! > >> > > >> > AFAICT, pstate file will contain something like > >> > > >> > 07: core 100 MHz memory 123 MHz * > >> > 08: core 100-200 MHz memory 123 MHz > >> > > >> > ...which does not look exactly like one-value-per-file, and I'm pretty > >> > sure userspace will get it wrong if it tries to parse it. Plus, I > >> > don't see required documentation in Documentation/ABI. > >> > > >> > Should we disable it for now, so that userspace does not start > >> > depending on it and we'll not have to maintain it forever? > >> > > >> > I guess better interface would be something like > >> > > >> > pstate/07/core_clock_min > >> > core_clock_max > >> > memory_clock_min > >> > memory_clock_max > >> > > >> > and then pstate/active containing just the number of active state? > Could we just say that the format of this file is one-per-line of > > level: information-for-the-user But it is not. Management tools will want to parse it, sooner or later. What is wrong with solution described above? > And you can echo a level into it to switch to that level? That seems > like a reasonable ABI to have... would be happy to throw it into a > file somewhere... not sure where though. Documentation/ABI/testing/ Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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/