[3.16.y-ckt extended stable] Patch "cpufreq: expose scaling_cur_freq sysfs file for set_policy() drivers" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    cpufreq: expose scaling_cur_freq sysfs file for set_policy() drivers

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt1.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 98198820e52f47b14e15c64cc543e2c7d3d5c6ae Mon Sep 17 00:00:00 2001
From: Dirk Brandewie <dirk.j.brandewie at intel.com>
Date: Mon, 13 Oct 2014 08:37:40 -0700
Subject: cpufreq: expose scaling_cur_freq sysfs file for set_policy() drivers

commit c034b02e213d271b98c45c4a7b54af8f69aaac1e upstream.

Currently the core does not expose scaling_cur_freq for set_policy()
drivers this breaks some userspace monitoring tools.
Change the core to expose this file for all drivers and if the
set_policy() driver supports the get() callback use it to retrieve the
current frequency.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=73741
Signed-off-by: Dirk Brandewie <dirk.j.brandewie at intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/cpufreq/cpufreq.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 21ab8bcd4d20..c06668f4e8c1 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -512,7 +512,18 @@ show_one(cpuinfo_max_freq, cpuinfo.max_freq);
 show_one(cpuinfo_transition_latency, cpuinfo.transition_latency);
 show_one(scaling_min_freq, min);
 show_one(scaling_max_freq, max);
-show_one(scaling_cur_freq, cur);
+
+static ssize_t show_scaling_cur_freq(
+	struct cpufreq_policy *policy, char *buf)
+{
+	ssize_t ret;
+
+	if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get)
+		ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu));
+	else
+		ret = sprintf(buf, "%u\n", policy->cur);
+	return ret;
+}

 static int cpufreq_set_policy(struct cpufreq_policy *policy,
 				struct cpufreq_policy *new_policy);
@@ -906,11 +917,11 @@ static int cpufreq_add_dev_interface(struct cpufreq_policy *policy,
 		if (ret)
 			goto err_out_kobj_put;
 	}
-	if (has_target()) {
-		ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
-		if (ret)
-			goto err_out_kobj_put;
-	}
+
+	ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
+	if (ret)
+		goto err_out_kobj_put;
+
 	if (cpufreq_driver->bios_limit) {
 		ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
 		if (ret)
--
2.1.0