From: Dirk Brandewie <dirk.j.brandewie@intel.com>
Date: Thu, 8 May 2014 19:57:24 +0000 (-0700)
Subject: intel_pstate: remove setting P state to MAX on init
X-Git-Tag: submit/tizen_common/20140730.172411~623
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=23de3167679e331f65d9aebdfb07fbf4f2167a4c;p=profile%2Fivi%2Fkernel-x86-ivi.git

intel_pstate: remove setting P state to MAX on init

commit d40a63c45b506b0681918d7c62a15cc9d48c8681 upstream.

Setting the P state of the core to max at init time is a hold over
from early implementation of intel_pstate where intel_pstate disabled
cpufreq and loaded VERY early in the boot sequence.  This was to
ensure that intel_pstate did not affect boot time. This in not needed
now that intel_pstate is a cpufreq driver.

Removing this covers the case where a CPU has gone through a manual
CPU offline/online cycle and the P state is set to MAX on init and the
CPU immediately goes idle.  Due to HW coordination the P state request
on the idle CPU will drag all cores to MAX P state until the load is
reevaluated when to core goes non-idle.

Reported-by: Patrick Marlier <patrick.marlier@gmail.com>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 6ed26ca..9ac3783 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -555,12 +555,7 @@ static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
 
 	if (pstate_funcs.get_vid)
 		pstate_funcs.get_vid(cpu);
-
-	/*
-	 * goto max pstate so we don't slow up boot if we are built-in if we are
-	 * a module we will take care of it during normal operation
-	 */
-	intel_pstate_set_pstate(cpu, cpu->pstate.max_pstate);
+	intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate);
 }
 
 static inline void intel_pstate_calc_busy(struct cpudata *cpu,
@@ -706,11 +701,6 @@ static int intel_pstate_init_cpu(unsigned int cpunum)
 	cpu = all_cpu_data[cpunum];
 
 	intel_pstate_get_cpu_pstates(cpu);
-	if (!cpu->pstate.current_pstate) {
-		all_cpu_data[cpunum] = NULL;
-		kfree(cpu);
-		return -ENODATA;
-	}
 
 	cpu->cpu = cpunum;
 
@@ -721,7 +711,6 @@ static int intel_pstate_init_cpu(unsigned int cpunum)
 	cpu->timer.expires = jiffies + HZ/100;
 	intel_pstate_busy_pid_reset(cpu);
 	intel_pstate_sample(cpu);
-	intel_pstate_set_pstate(cpu, cpu->pstate.max_pstate);
 
 	add_timer_on(&cpu->timer, cpunum);