Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758033Ab1FPRGX (ORCPT ); Thu, 16 Jun 2011 13:06:23 -0400 Received: from s15228384.onlinehome-server.info ([87.106.30.177]:60570 "EHLO mail.x86-64.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757687Ab1FPRGP (ORCPT ); Thu, 16 Jun 2011 13:06:15 -0400 Date: Thu, 16 Jun 2011 19:06:11 +0200 From: Borislav Petkov To: Konrad Rzeszutek Wilk Cc: linux-kernel@vger.kernel.org, davej@redhat.com, x86@kernel.org, cpufreq@vger.kernel.org, bp@alien8.de, andre.przywara@amd.com, Mark.Langsdorf@amd.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com Subject: Re: [PATCH] [CPUFREQ] powernow-k8: Don't try to transition if the pstate is incorrect or there is no freq for it. Message-ID: <20110616170611.GA18407@gere.osrc.amd.com> References: <1308164520-14145-1-git-send-email-konrad.wilk@oracle.com> <20110616142829.GB5576@dumpdata.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110616142829.GB5576@dumpdata.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2541 Lines: 76 On Thu, Jun 16, 2011 at 10:28:29AM -0400, Konrad Rzeszutek Wilk wrote: > > And as mentioned, the other patch that just deals with pstates. > > From 0f3bc30b6bc7dad62e3b77063b69df44ca9a9f8e Mon Sep 17 00:00:00 2001 > From: Konrad Rzeszutek Wilk > Date: Wed, 15 Jun 2011 11:08:02 -0400 > Subject: [PATCH] [CPUFREQ] powernow-k8: Don't try to transition if the pstate is incorrect or there is no freq for it. > > This patch auguments the pstate transition code to error out augments > (instead of returning 0) when a incorrect pstate is provided. an > It also checks whether the frequency for the pstate is > incorrect and if so errors out. > > Suggested-by: Borislav Petkov > CC: andre.przywara@amd.com > CC: Mark.Langsdorf@amd.com > Signed-off-by: Konrad Rzeszutek Wilk > --- > drivers/cpufreq/powernow-k8.c | 6 +++++- > 1 files changed, 5 insertions(+), 1 deletions(-) > > diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c > index fe53572..047c7b11 100644 > --- a/drivers/cpufreq/powernow-k8.c > +++ b/drivers/cpufreq/powernow-k8.c > @@ -1103,11 +1103,15 @@ static int transition_frequency_pstate(struct powernow_k8_data *data, > /* get MSR index for hardware pstate transition */ > pstate = index & HW_PSTATE_MASK; > if (pstate > data->max_hw_pstate) > - return 0; > + return -EINVAL; > + Hehe, this was a bug, actually, good catch! powernowk8_target is actually considering ret = 0 a success and ret != 0 a failure but we were returning a 0 when our target pstate is bogus. > freqs.old = find_khz_freq_from_pstate(data->powernow_table, > data->currpstate); > freqs.new = find_khz_freq_from_pstate(data->powernow_table, pstate); > > + if (freqs.new == CPUFREQ_ENTRY_INVALID) > + return -EINVAL; > + No need for that since freqs.new is determined from pstate and you're checking pstate above. > for_each_cpu(i, data->available_cores) { > freqs.cpu = i; > cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); Thanks. -- Regards/Gruss, Boris. Advanced Micro Devices GmbH Einsteinring 24, 85609 Dornach General Managers: Alberto Bozzo, Andrew Bowd Registration: Dornach, Gemeinde Aschheim, Landkreis Muenchen Registergericht Muenchen, HRB Nr. 43632 -- 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/