From: Stanislaw Gruszka <sgruszka@redhat.com>
Date: Tue, 28 Jul 2009 08:13:17 +0200
Subject: [cpufreq] P-state limit: limit can never be increased
Message-id: 20090728081317.464a1485@dhcp-lab-109.englab.brq.redhat.com
O-Subject: [RHEL5.5 PATCH V2] BZ489566: when booted with P-state limit, limit can never be increased
Bugzilla: 489566
RH-Acked-by: Danny Feng <dfeng@redhat.com>
RH-Acked-by: Jiri Pirko <jpirko@redhat.com>
RH-Acked-by: Stefan Assmann <sassmann@redhat.com>
RH-Acked-by: Dean Nelson <dnelson@redhat.com>
RH-Acked-by: Prarit Bhargava <prarit@redhat.com>
RH-Acked-by: Anton Arapov <aarapov@redhat.com>
RH-Acked-by: Jiri Pirko <jpirko@redhat.com>

BZ#489566
=========
https://bugzilla.redhat.com/show_bug.cgi?id=489566

Description:
============
If cpufreq driver initialize when BIOS limits P-states, cpufreq_set_policy()
function limits also policy->user_policy.max . User never can increase
cpu frequency beyond this limit even if BIOS allows to use higher frequencies
later.

Compering to previous patch we call blocking_notifier_call_chain() after
the policy->user_policy fields are set, like in upstream.

kABI Status:
============
No symbols were harmed.

Brew:
====
https://brewweb.devel.redhat.com/taskinfo?taskID=1906929

Upstream Status:
===============
This patch is backport of:

commit: 22c970f3468a6766b362d57fa32ebb92cb8cd6db
Author: Thomas Renninger <trenn@suse.de>
Date:   Thu Apr 19 15:48:34 2007 +0200

    [CPUFREQ] Fix limited cpufreq when booted on battery

Test Status:
============
Tested by me on remote system provided by partner.

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 47442d4..25cdd2c 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -735,6 +735,9 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
 		unlock_policy_rwsem_write(cpu);
 		goto err_out;
 	}
+	policy->user_policy.min = policy->cpuinfo.min_freq;
+	policy->user_policy.max = policy->cpuinfo.max_freq;
+	policy->user_policy.governor = policy->governor;
 
 	blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
 				     CPUFREQ_START, policy);
@@ -819,10 +822,13 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
 
 	policy->governor = NULL; /* to assure that the starting sequence is
 				  * run in cpufreq_set_policy */
-	unlock_policy_rwsem_write(cpu);
 
 	/* set default policy */
-	ret = cpufreq_set_policy(&new_policy);
+	ret = __cpufreq_set_policy(policy, &new_policy);
+	policy->user_policy.policy = policy->policy;
+
+	unlock_policy_rwsem_write(cpu);
+
 	if (ret) {
 		dprintk("setting policy failed\n");
 		goto err_out_unregister;