Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932294AbaFWN3y (ORCPT ); Mon, 23 Jun 2014 09:29:54 -0400 Received: from mail-oa0-f42.google.com ([209.85.219.42]:48020 "EHLO mail-oa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754944AbaFWN3v (ORCPT ); Mon, 23 Jun 2014 09:29:51 -0400 MIME-Version: 1.0 In-Reply-To: <20140623130259.GA29809@amd.pavel.ucw.cz> References: <20140621180201.GA4621@amd.pavel.ucw.cz> <20140621194538.GA4903@kroah.com> <20140623130259.GA29809@amd.pavel.ucw.cz> Date: Mon, 23 Jun 2014 09:29:51 -0400 X-Google-Sender-Auth: S0paDUbk8vXnU46-ULB_5HgwdMk Message-ID: Subject: Re: unparseable, undocumented /sys/class/drm/.../pstate From: Ilia Mirkin To: Pavel Machek Cc: Greg KH , kernel list , Ben Skeggs , Alexandre Courbot , David Airlie , "dri-devel@lists.freedesktop.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 23, 2014 at 9:02 AM, Pavel Machek wrote: > 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. But it is... > Management tools will want to parse it, sooner or > later. What is wrong with solution described above? It is complex and annoying to the people that will actually use it. > >> 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/ Yes, I got that far. And then I became confused. -ilia -- 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/