Re: [Bug 55411] sysfs per-cpu cpufreq subdirs/symlinks screwed up after s2ram

Viresh Kumar
2013-03-24T12:23:41Z

[-- Attachment #1: Type: text/plain, Size: 510 bytes --]

On 24 March 2013 17:46, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> Fixing Duncan's issues shouldn't be a very big deal now as i was thinking too
> much about what was broken without my patches too. And now that part is
> pretty clear.

Hi Duncan,

Try attached patch and this should take back your system to where it was.

NOTE: With this patch your related_cpus wouldn't show any groups and
related cpus must be same as affected cpus. All cpu*/cpufreq must be
directories now and no symlinks.

--
viresh

[-- Attachment #2: 0001-cpufreq-acpi-cpufreq-Don-t-set-policy-related_cpus-f.patch --]
[-- Type: application/octet-stream, Size: 1935 bytes --]

From 0eb6a6ce25c71e60dc69e1897f80b7ce3bb41fb2 Mon Sep 17 00:00:00 2001
Message-Id: <0eb6a6ce25c71e60dc69e1897f80b7ce3bb41fb2.1364127667.git.viresh.kumar@linaro.org>
From: Viresh Kumar <viresh.kumar@linaro.org>
Date: Sat, 23 Mar 2013 23:42:44 +0530
Subject: [PATCH] cpufreq: acpi-cpufreq: Don't set policy->related_cpus from
.init()

With the addition of following patch:

fcf8058 cpufreq: Simplify cpufreq_add_dev()

cpufreq driver's .init() routine must initialize policy->cpus with mask of all
possible cpus (Online + Offline) that share the clock. Then the core would copy
this mask onto policy->related_cpus and will reset policy->cpus to carry only
online cpus.

acpi-cpufreq driver wasn't updated with this assumption and so sometimes when
we try to hot[un]plug cpus at run time, sysfs directories gets corrupted.

This patch fixes acpi-cpufreq driver against this corruption.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
drivers/cpufreq/acpi-cpufreq.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index afbef9c..11b8b4b 100644
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -723,7 +723,6 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
cpumask_copy(policy->cpus, perf->shared_cpu_map);
}
- cpumask_copy(policy->related_cpus, perf->shared_cpu_map);

#ifdef CONFIG_SMP
dmi_check_system(sw_any_bug_dmi_table);
@@ -735,7 +734,6 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
cpumask_clear(policy->cpus);
cpumask_set_cpu(cpu, policy->cpus);
- cpumask_copy(policy->related_cpus, cpu_sibling_mask(cpu));
policy->shared_type = CPUFREQ_SHARED_TYPE_HW;
pr_info_once(PFX "overriding BIOS provided _PSD data\n");
}
--
1.7.12.rc2.18.g61b472e