Commit fe829ed8 authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki
Browse files

cpufreq: Add CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING cpufreq driver flag 



The policy->transition_latency field is used for multiple purposes
today and its not straight forward at all. This is how it is used:

A. Set the correct transition_latency value.

B. Set it to CPUFREQ_ETERNAL because:
   1. We don't want automatic dynamic switching (with
      ondemand/conservative) to happen at all.
   2. We don't know the transition latency.

This patch handles the B.1. case in a more readable way. A new flag for
the cpufreq drivers is added to disallow use of cpufreq governors which
have dynamic_switching flag set.

All the current cpufreq drivers which are setting transition_latency
unconditionally to CPUFREQ_ETERNAL are updated to use it. They don't
need to set transition_latency anymore.

There shouldn't be any functional change after this patch.

Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: default avatarDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 560c6e45

drivers/cpufreq/cpufreq-nforce2.c

+1 −1
Original line number Diff line number Diff line
@@ -357,7 +357,6 @@ static int nforce2_cpu_init(struct cpufreq_policy *policy) 
	/* cpuinfo and default policy values */

	policy->min = policy->cpuinfo.min_freq = min_fsb * fid * 100;

	policy->max = policy->cpuinfo.max_freq = max_fsb * fid * 100;

	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;



	return 0;

}
@@ -369,6 +368,7 @@ static int nforce2_cpu_exit(struct cpufreq_policy *policy) 


static struct cpufreq_driver nforce2_driver = {

	.name = "nforce2",

	.flags = CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,

	.verify = nforce2_verify,

	.target = nforce2_target,

	.get = nforce2_get,

drivers/cpufreq/cpufreq.c

+3 −2
Original line number Diff line number Diff line
@@ -2005,11 +2005,12 @@ static int cpufreq_init_governor(struct cpufreq_policy *policy) 


	/* Platform doesn't want dynamic frequency switching ? */

	if (policy->governor->dynamic_switching &&

	    policy->cpuinfo.transition_latency == CPUFREQ_ETERNAL) {

	    (cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING ||

	    policy->cpuinfo.transition_latency == CPUFREQ_ETERNAL)) {

		struct cpufreq_governor *gov = cpufreq_fallback_governor();



		if (gov) {

			pr_warn("Transition latency set to CPUFREQ_ETERNAL, can't use %s governor. Fallback to %s governor\n",

			pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n",

				policy->governor->name, gov->name);

			policy->governor = gov;

		} else {

drivers/cpufreq/elanfreq.c

+1 −3
Original line number Diff line number Diff line
@@ -165,9 +165,6 @@ static int elanfreq_cpu_init(struct cpufreq_policy *policy) 
		if (pos->frequency > max_freq)

			pos->frequency = CPUFREQ_ENTRY_INVALID;



	/* cpuinfo and default policy values */

	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;



	return cpufreq_table_validate_and_show(policy, elanfreq_table);

}
@@ -196,6 +193,7 @@ __setup("elanfreq=", elanfreq_setup); 


static struct cpufreq_driver elanfreq_driver = {

	.get		= elanfreq_get_cpu_frequency,

	.flags		= CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,

	.verify		= cpufreq_generic_frequency_table_verify,

	.target_index	= elanfreq_target,

	.init		= elanfreq_cpu_init,

drivers/cpufreq/gx-suspmod.c

+1 −1
Original line number Diff line number Diff line
@@ -428,7 +428,6 @@ static int cpufreq_gx_cpu_init(struct cpufreq_policy *policy) 
	policy->max = maxfreq;

	policy->cpuinfo.min_freq = maxfreq / max_duration;

	policy->cpuinfo.max_freq = maxfreq;

	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;



	return 0;

}
@@ -438,6 +437,7 @@ static int cpufreq_gx_cpu_init(struct cpufreq_policy *policy) 
 *   MediaGX/Geode GX initialize cpufreq driver

 */

static struct cpufreq_driver gx_suspmod_driver = {

	.flags		= CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,

	.get		= gx_get_cpuspeed,

	.verify		= cpufreq_gx_verify,

	.target		= cpufreq_gx_target,

drivers/cpufreq/pmac32-cpufreq.c

+5 −2
Original line number Diff line number Diff line
@@ -442,7 +442,8 @@ static struct cpufreq_driver pmac_cpufreq_driver = { 
	.init		= pmac_cpufreq_cpu_init,

	.suspend	= pmac_cpufreq_suspend,

	.resume		= pmac_cpufreq_resume,

	.flags		= CPUFREQ_PM_NO_WARN,

	.flags		= CPUFREQ_PM_NO_WARN |

			  CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,

	.attr		= cpufreq_generic_attr,

	.name		= "powermac",

};
@@ -626,14 +627,16 @@ static int __init pmac_cpufreq_setup(void) 
	if (!value)

		goto out;

	cur_freq = (*value) / 1000;

	transition_latency = CPUFREQ_ETERNAL;



	/*  Check for 7447A based MacRISC3 */

	if (of_machine_is_compatible("MacRISC3") &&

	    of_get_property(cpunode, "dynamic-power-step", NULL) &&

	    PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {

		pmac_cpufreq_init_7447A(cpunode);



		/* Allow dynamic switching */

		transition_latency = 8000000;

		pmac_cpufreq_driver.flags &= ~CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING;

	/* Check for other MacRISC3 machines */

	} else if (of_machine_is_compatible("PowerBook3,4") ||

		   of_machine_is_compatible("PowerBook3,5") ||

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