This is a note to let you know that I've just added the patch titled
cpufreq: unlock when failing cpufreq_update_policy()
to the 3.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cpufreq-unlock-when-failing-cpufreq_update_policy.patch
and it can be found in the queue-3.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From fefa8ff810c5ab4c4206aed9d159c4d6fe8d4f1c Mon Sep 17 00:00:00 2001
From: Aaron Plattner <aplattner@xxxxxxxxxx>
Date: Wed, 18 Jun 2014 11:27:32 -0700
Subject: cpufreq: unlock when failing cpufreq_update_policy()
From: Aaron Plattner <aplattner@xxxxxxxxxx>
commit fefa8ff810c5ab4c4206aed9d159c4d6fe8d4f1c upstream.
Commit bd0fa9bb455d introduced a failure path to cpufreq_update_policy() if
cpufreq_driver->get(cpu) returns NULL. However, it jumps to the 'no_policy'
label, which exits without unlocking any of the locks the function acquired
earlier. This causes later calls into cpufreq to hang.
Fix this by creating a new 'unlock' label and jumping to that instead.
Fixes: bd0fa9bb455d ("cpufreq: Return error if ->get() failed in cpufreq_update_policy()")
Link: https://devtalk.nvidia.com/default/topic/751903/kernel-3-15-and-nv-drivers-337-340-failed-to-initialize-the-nvidia-kernel-module-gtx-550-ti-/
Signed-off-by: Aaron Plattner <aplattner@xxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/cpufreq/cpufreq.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -2166,10 +2166,8 @@ int cpufreq_update_policy(unsigned int c
struct cpufreq_policy new_policy;
int ret;
- if (!policy) {
- ret = -ENODEV;
- goto no_policy;
- }
+ if (!policy)
+ return -ENODEV;
down_write(&policy->rwsem);
@@ -2188,7 +2186,7 @@ int cpufreq_update_policy(unsigned int c
new_policy.cur = cpufreq_driver->get(cpu);
if (WARN_ON(!new_policy.cur)) {
ret = -EIO;
- goto no_policy;
+ goto unlock;
}
if (!policy->cur) {
@@ -2203,10 +2201,10 @@ int cpufreq_update_policy(unsigned int c
ret = cpufreq_set_policy(policy, &new_policy);
+unlock:
up_write(&policy->rwsem);
cpufreq_cpu_put(policy);
-no_policy:
return ret;
}
EXPORT_SYMBOL(cpufreq_update_policy);
Patches currently in stable-queue which might be from aplattner@xxxxxxxxxx are
queue-3.15/cpufreq-unlock-when-failing-cpufreq_update_policy.patch
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