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authorJacob Shin <jacob.shin@amd.com>2011-04-27 22:32:11 +0400
committerDave Jones <davej@redhat.com>2011-05-04 19:50:57 +0400
commit27ecddc2a9f99ce4ac9a59a0acd77f7100b6d034 (patch)
tree941daeb656c519deeb8e0bd853944536e34ab80e /drivers/cpufreq
parent904cc1e637a00dba1b58e7752f485f90ebf2a568 (diff)
downloadlinux-27ecddc2a9f99ce4ac9a59a0acd77f7100b6d034.tar.xz
[CPUFREQ] CPU hotplug, re-create sysfs directory and symlinks
When we discover CPUs that are affected by each other's frequency/voltage transitions, the first CPU gets a sysfs directory created, and rest of the siblings get symlinks. Currently, when we hotplug off only the first CPU, all of the symlinks and the sysfs directory gets removed. Even though rest of the siblings are still online and functional, they are orphaned, and no longer governed by cpufreq. This patch, given the above scenario, creates a sysfs directory for the first sibling and symlinks for the rest of the siblings. Please note the recursive call, it was rather too ugly to roll it out. And the removal of redundant NULL setting (it is already taken care of near the top of the function). Signed-off-by: Jacob Shin <jacob.shin@amd.com> Acked-by: Mark Langsdorf <mark.langsdorf@amd.com> Reviewed-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com> Cc: stable@kernel.org
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/cpufreq.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 2dafc5c38ae7..7c10f96c5ae9 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1208,12 +1208,28 @@ static int __cpufreq_remove_dev(struct sys_device *sys_dev)
cpufreq_driver->exit(data);
unlock_policy_rwsem_write(cpu);
+ cpufreq_debug_enable_ratelimit();
+
+#ifdef CONFIG_HOTPLUG_CPU
+ /* when the CPU which is the parent of the kobj is hotplugged
+ * offline, check for siblings, and create cpufreq sysfs interface
+ * and symlinks
+ */
+ if (unlikely(cpumask_weight(data->cpus) > 1)) {
+ /* first sibling now owns the new sysfs dir */
+ cpumask_clear_cpu(cpu, data->cpus);
+ cpufreq_add_dev(get_cpu_sysdev(cpumask_first(data->cpus)));
+
+ /* finally remove our own symlink */
+ lock_policy_rwsem_write(cpu);
+ __cpufreq_remove_dev(sys_dev);
+ }
+#endif
+
free_cpumask_var(data->related_cpus);
free_cpumask_var(data->cpus);
kfree(data);
- per_cpu(cpufreq_cpu_data, cpu) = NULL;
- cpufreq_debug_enable_ratelimit();
return 0;
}