Commit d394abcb authored by Shivnandan Kumar's avatar Shivnandan Kumar Committed by Rafael J. Wysocki
Browse files

cpufreq: Limit resolving a frequency to policy min/max 



Resolving a frequency to an efficient one should not transgress
policy->max (which can be set for thermal reason) and policy->min.

Currently, there is possibility where scaling_cur_freq can exceed
scaling_max_freq when scaling_max_freq is an inefficient frequency.

Add a check to ensure that resolving a frequency will respect
policy->min/max.

Cc: All applicable <stable@vger.kernel.org>
Fixes: 1f39fa0d ("cpufreq: Introducing CPUFREQ_RELATION_E")
Signed-off-by: default avatarShivnandan Kumar <quic_kshivnan@quicinc.com>
[ rjw: Whitespace adjustment, changelog edits ]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 8164f743

include/linux/cpufreq.h

+14 −1
Original line number Diff line number Diff line
@@ -1020,6 +1020,18 @@ static inline int cpufreq_table_find_index_c(struct cpufreq_policy *policy, 
						   efficiencies);

}



static inline bool cpufreq_is_in_limits(struct cpufreq_policy *policy, int idx)

{

	unsigned int freq;



	if (idx < 0)

		return false;



	freq = policy->freq_table[idx].frequency;



	return freq == clamp_val(freq, policy->min, policy->max);

}



static inline int cpufreq_frequency_table_target(struct cpufreq_policy *policy,

						 unsigned int target_freq,

						 unsigned int relation)
@@ -1053,7 +1065,8 @@ static inline int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 
		return 0;

	}



	if (idx < 0 && efficiencies) {

	/* Limit frequency index to honor policy->min/max */

	if (!cpufreq_is_in_limits(policy, idx) && efficiencies) {

		efficiencies = false;

		goto retry;

	}