Commit 6afde10c authored by Thomas Renninger's avatar Thomas Renninger Committed by Dave Jones
Browse files

[CPUFREQ] Only check for transition latency on problematic governors (kconfig fix) 



Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarDave Jones <davej@redhat.com>
parent 1c256245

drivers/cpufreq/cpufreq.c

+20 −7
Original line number Diff line number Diff line
@@ -1484,11 +1484,23 @@ static int __cpufreq_governor(struct cpufreq_policy *policy, 
					unsigned int event)

{

	int ret;

	struct cpufreq_governor *gov = CPUFREQ_PERFORMANCE_GOVERNOR;



	/* Only must be defined when default governor is known to have latency

	   restrictions, like e.g. conservative or ondemand.

	   That this is the case is already ensured in Kconfig

	*/

#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE

	struct cpufreq_governor *gov = &cpufreq_gov_performance;

#else

	struct cpufreq_governor *gov = NULL;

#endif



	if (policy->governor->max_transition_latency &&

	    policy->cpuinfo.transition_latency >

	    policy->governor->max_transition_latency) {

		if (!gov)

			return -EINVAL;

		else {

			printk(KERN_WARNING "%s governor failed, too long"

			       " transition latency of HW, fallback"

			       " to %s governor\n",
@@ -1496,6 +1508,7 @@ static int __cpufreq_governor(struct cpufreq_policy *policy, 
			       gov->name);

			policy->governor = gov;

		}

	}



	if (!try_module_get(policy->governor->owner))

		return -EINVAL;

include/linux/cpufreq.h

+2 −1
Original line number Diff line number Diff line
@@ -286,8 +286,9 @@ static inline unsigned int cpufreq_quick_get(unsigned int cpu) 
  Performance governor is fallback governor if any other gov failed to

  auto load due latency restrictions

*/

#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE

extern struct cpufreq_governor cpufreq_gov_performance;

#define CPUFREQ_PERFORMANCE_GOVERNOR	(&cpufreq_gov_performance)

#endif

#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE

#define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_performance)

#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)