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From d394abcb12bb1a6f309c1221fdb8e73594ecf1b4 Mon Sep 17 00:00:00 2001
From: Shivnandan Kumar <quic_kshivnan@quicinc.com>
Date: Tue, 27 Feb 2024 14:43:51 +0530
Subject: [PATCH] cpufreq: Limit resolving a frequency to policy min/max
Git-commit: d394abcb12bb1a6f309c1221fdb8e73594ecf1b4
Patch-mainline: v6.9-rc1
References: git-fixes

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: 1f39fa0dccff ("cpufreq: Introducing CPUFREQ_RELATION_E")
Signed-off-by: Shivnandan Kumar <quic_kshivnan@quicinc.com>
[ rjw: Whitespace adjustment, changelog edits ]

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 include/linux/cpufreq.h | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 85908b3a2f24..692ea6e55129 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -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;
 	}
-- 
2.43.0