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authorJacob Shin <jacob.shin@amd.com>2011-04-27 13:32:11 -0500
committerEric Miao <eric.miao@canonical.com>2011-11-10 07:39:02 +0800
commited13fe299d4b4b7312b9b6f84290bc69db87ade9 (patch)
tree3afde5734fb1561eb8369697ce95f2ec508a16af
parentd990de15fae67ea14c60a27bcd8e58e42f062d62 (diff)
downloadlinux-linaro-ed13fe299d4b4b7312b9b6f84290bc69db87ade9.tar.gz
CPU hotplug, re-create sysfs directory and symlinks
commit 27ecddc2a9f99ce4ac9a59a0acd77f7100b6d034 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> (cherry picked from commit 15ae4738537b75bb8f9ba737bcb18c8cb0cb1e07)
-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 5cb4d09919d..f06a3b9b5f1 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1207,12 +1207,28 @@ 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;
}