From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932086AbaCYRWP (ORCPT ); Tue, 25 Mar 2014 13:22:15 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:55953 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755157AbaCYRWF (ORCPT ); Tue, 25 Mar 2014 13:22:05 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "Srivatsa S. Bhat" , "Rafael J. Wysocki" , Kamal Mostafa Subject: [PATCH 3.8 42/81] cpufreq: powernow-k8: Initialize per-cpu data-structures properly Date: Tue, 25 Mar 2014 10:15:55 -0700 Message-Id: <1395767794-5012-43-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1395767794-5012-1-git-send-email-kamal@canonical.com> References: <1395767794-5012-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.8.13.20 -stable review patch. If anyone has any objections, please let me know. ------------------ From: "Srivatsa S. Bhat" commit c3274763bfc3bf1ececa269ed6e6c4d7ec1c3e5e upstream. The powernow-k8 driver maintains a per-cpu data-structure called powernow_data that is used to perform the frequency transitions. It initializes this data structure only for the policy->cpu. So, accesses to this data structure by other CPUs results in various problems because they would have been uninitialized. Specifically, if a cpu (!= policy->cpu) invokes the drivers' ->get() function, it returns 0 as the KHz value, since its per-cpu memory doesn't point to anything valid. This causes problems during suspend/resume since cpufreq_update_policy() tries to enforce this (0 KHz) as the current frequency of the CPU, and this madness gets propagated to adjust_jiffies() as well. Eventually, lots of things start breaking down, including the r8169 ethernet card, in one particularly interesting case reported by Pierre Ossman. Fix this by initializing the per-cpu data-structures of all the CPUs in the policy appropriately. References: https://bugzilla.kernel.org/show_bug.cgi?id=70311 Reported-by: Pierre Ossman Signed-off-by: Srivatsa S. Bhat Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki Signed-off-by: Kamal Mostafa --- drivers/cpufreq/powernow-k8.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c index 056faf6..69bf037 100644 --- a/drivers/cpufreq/powernow-k8.c +++ b/drivers/cpufreq/powernow-k8.c @@ -1102,7 +1102,7 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol) { struct powernow_k8_data *data; struct init_on_cpu init_on_cpu; - int rc; + int rc, cpu; if (!cpu_online(pol->cpu)) return -ENODEV; @@ -1174,7 +1174,9 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol) pr_debug("cpu_init done, current fid 0x%x, vid 0x%x\n", data->currfid, data->currvid); - per_cpu(powernow_data, pol->cpu) = data; + /* Point all the CPUs in this policy to the same data */ + for_each_cpu(cpu, pol->cpus) + per_cpu(powernow_data, cpu) = data; return 0; @@ -1189,6 +1191,7 @@ err_out: static int powernowk8_cpu_exit(struct cpufreq_policy *pol) { struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu); + int cpu; if (!data) return -EINVAL; @@ -1199,7 +1202,8 @@ static int powernowk8_cpu_exit(struct cpufreq_policy *pol) kfree(data->powernow_table); kfree(data); - per_cpu(powernow_data, pol->cpu) = NULL; + for_each_cpu(cpu, pol->cpus) + per_cpu(powernow_data, cpu) = NULL; return 0; } -- 1.8.3.2