Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754341AbaFUTp5 (ORCPT ); Sat, 21 Jun 2014 15:45:57 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:58711 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752351AbaFUTpz (ORCPT ); Sat, 21 Jun 2014 15:45:55 -0400 X-Sasl-enc: YHm9v08nJ6rvMsYy0N3btfsaGA/DpE7fz7a32/jIds5V 1403379954 Date: Sat, 21 Jun 2014 12:45:38 -0700 From: Greg KH To: Ilia Mirkin Cc: Pavel Machek , kernel list , Ben Skeggs , Alexandre Courbot , David Airlie , "dri-devel@lists.freedesktop.org" Subject: Re: unparseable, undocumented /sys/class/drm/.../pstate Message-ID: <20140621194538.GA4903@kroah.com> References: <20140621180201.GA4621@amd.pavel.ucw.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? > > > > Thanks, > > Pavel > > > > PS: I have no nvidia, got the news at > > > > http://www.phoronix.com/scan.php?page=article&item=nouveau_try_linux316&num=2 > > FTR, this file has been in place since 3.13, and there was a different > file before it (performance_levels), with a comparable format since > much earlier (definitely 3.8, probably earlier). I think it's meant a > lot more for people looking at it and echo'ing stuff to it to modify > the levels (where supported), than for programs parsing it. Perhaps > sysfs is the wrong place for this -- what is the right place? debugfs? Yes, please move it to debugfs. greg k-h -- 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/