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Message-ID: <5896780.DvuYhMxLoT@rjwysocki.net>
Date: Fri, 25 Apr 2025 13:36:21 +0200
From: "Rafael J. Wysocki" <rjw@...ysocki.net>
To: Linux PM <linux-pm@...r.kernel.org>
Cc: Christian Loehle <christian.loehle@....com>,
LKML <linux-kernel@...r.kernel.org>, Viresh Kumar <viresh.kumar@...aro.org>,
Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
Mario Limonciello <mario.limonciello@....com>,
Sultan Alsawaf <sultan@...neltoast.com>,
Stephan Gerhold <stephan.gerhold@...aro.org>,
"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>
Subject:
[PATCH v2] cpufreq: Fix setting policy limits when frequency tables are used
From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Commit 7491cdf46b5c ("cpufreq: Avoid using inconsistent policy->min and
policy->max") overlooked the fact that policy->min and policy->max were
accessed directly in cpufreq_frequency_table_target() and in the
functions called by it. Consequently, the changes made by that commit
led to problems with setting policy limits.
Address this by passing the target frequency limits to __resolve_freq()
and cpufreq_frequency_table_target() and propagating them to the
functions called by the latter.
Fixes: 7491cdf46b5c ("cpufreq: Avoid using inconsistent policy->min and policy->max")
Link: https://lore.kernel.org/linux-pm/aAplED3IA_J0eZN0@linaro.org/
Reported-by: Stephan Gerhold <stephan.gerhold@...aro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
The v1 is here: https://lore.kernel.org/linux-pm/12665363.O9o76ZdvQC@rjwysocki.net/
v1 -> v2:
* Do clamp_val(target_freq, min, max) before checking freq_table against
NULL in __resolve_freq().
* Update comment in cpufreq_frequency_table_target() to match the new code.
---
drivers/cpufreq/cpufreq.c | 22 ++++++---
drivers/cpufreq/cpufreq_ondemand.c | 3 -
drivers/cpufreq/freq_table.c | 6 +-
include/linux/cpufreq.h | 83 ++++++++++++++++++++++++-------------
4 files changed, 73 insertions(+), 41 deletions(-)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -491,14 +491,18 @@
EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch);
static unsigned int __resolve_freq(struct cpufreq_policy *policy,
- unsigned int target_freq, unsigned int relation)
+ unsigned int target_freq,
+ unsigned int min, unsigned int max,
+ unsigned int relation)
{
unsigned int idx;
+ target_freq = clamp_val(target_freq, min, max);
+
if (!policy->freq_table)
return target_freq;
- idx = cpufreq_frequency_table_target(policy, target_freq, relation);
+ idx = cpufreq_frequency_table_target(policy, target_freq, min, max, relation);
policy->cached_resolved_idx = idx;
policy->cached_target_freq = target_freq;
return policy->freq_table[idx].frequency;
@@ -532,8 +536,7 @@
if (unlikely(min > max))
min = max;
- return __resolve_freq(policy, clamp_val(target_freq, min, max),
- CPUFREQ_RELATION_LE);
+ return __resolve_freq(policy, target_freq, min, max, CPUFREQ_RELATION_LE);
}
EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq);
@@ -2351,8 +2354,8 @@
if (cpufreq_disabled())
return -ENODEV;
- target_freq = clamp_val(target_freq, policy->min, policy->max);
- target_freq = __resolve_freq(policy, target_freq, relation);
+ target_freq = __resolve_freq(policy, target_freq, policy->min,
+ policy->max, relation);
pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
policy->cpu, target_freq, relation, old_target_freq);
@@ -2650,8 +2653,11 @@
* compiler optimizations around them because they may be accessed
* concurrently by cpufreq_driver_resolve_freq() during the update.
*/
- WRITE_ONCE(policy->max, __resolve_freq(policy, new_data.max, CPUFREQ_RELATION_H));
- new_data.min = __resolve_freq(policy, new_data.min, CPUFREQ_RELATION_L);
+ WRITE_ONCE(policy->max, __resolve_freq(policy, new_data.max,
+ new_data.min, new_data.max,
+ CPUFREQ_RELATION_H));
+ new_data.min = __resolve_freq(policy, new_data.min, new_data.min,
+ new_data.max, CPUFREQ_RELATION_L);
WRITE_ONCE(policy->min, new_data.min > policy->max ? policy->max : new_data.min);
trace_cpu_frequency_limits(policy);
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -76,7 +76,8 @@
return freq_next;
}
- index = cpufreq_frequency_table_target(policy, freq_next, relation);
+ index = cpufreq_frequency_table_target(policy, freq_next, policy->min,
+ policy->max, relation);
freq_req = freq_table[index].frequency;
freq_reduc = freq_req * od_tuners->powersave_bias / 1000;
freq_avg = freq_req - freq_reduc;
--- a/drivers/cpufreq/freq_table.c
+++ b/drivers/cpufreq/freq_table.c
@@ -115,8 +115,8 @@
EXPORT_SYMBOL_GPL(cpufreq_generic_frequency_table_verify);
int cpufreq_table_index_unsorted(struct cpufreq_policy *policy,
- unsigned int target_freq,
- unsigned int relation)
+ unsigned int target_freq, unsigned int min,
+ unsigned int max, unsigned int relation)
{
struct cpufreq_frequency_table optimal = {
.driver_data = ~0,
@@ -147,7 +147,7 @@
cpufreq_for_each_valid_entry_idx(pos, table, i) {
freq = pos->frequency;
- if ((freq < policy->min) || (freq > policy->max))
+ if (freq < min || freq > max)
continue;
if (freq == target_freq) {
optimal.driver_data = i;
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -788,8 +788,8 @@
int cpufreq_generic_frequency_table_verify(struct cpufreq_policy_data *policy);
int cpufreq_table_index_unsorted(struct cpufreq_policy *policy,
- unsigned int target_freq,
- unsigned int relation);
+ unsigned int target_freq, unsigned int min,
+ unsigned int max, unsigned int relation);
int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
unsigned int freq);
@@ -852,12 +852,12 @@
return best;
}
-/* Works only on sorted freq-tables */
-static inline int cpufreq_table_find_index_l(struct cpufreq_policy *policy,
- unsigned int target_freq,
- bool efficiencies)
+static inline int find_index_l(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int min, unsigned int max,
+ bool efficiencies)
{
- target_freq = clamp_val(target_freq, policy->min, policy->max);
+ target_freq = clamp_val(target_freq, min, max);
if (policy->freq_table_sorted == CPUFREQ_TABLE_SORTED_ASCENDING)
return cpufreq_table_find_index_al(policy, target_freq,
@@ -867,6 +867,14 @@
efficiencies);
}
+/* Works only on sorted freq-tables */
+static inline int cpufreq_table_find_index_l(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ bool efficiencies)
+{
+ return find_index_l(policy, target_freq, policy->min, policy->max, efficiencies);
+}
+
/* Find highest freq at or below target in a table in ascending order */
static inline int cpufreq_table_find_index_ah(struct cpufreq_policy *policy,
unsigned int target_freq,
@@ -920,12 +928,12 @@
return best;
}
-/* Works only on sorted freq-tables */
-static inline int cpufreq_table_find_index_h(struct cpufreq_policy *policy,
- unsigned int target_freq,
- bool efficiencies)
+static inline int find_index_h(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int min, unsigned int max,
+ bool efficiencies)
{
- target_freq = clamp_val(target_freq, policy->min, policy->max);
+ target_freq = clamp_val(target_freq, min, max);
if (policy->freq_table_sorted == CPUFREQ_TABLE_SORTED_ASCENDING)
return cpufreq_table_find_index_ah(policy, target_freq,
@@ -935,6 +943,14 @@
efficiencies);
}
+/* Works only on sorted freq-tables */
+static inline int cpufreq_table_find_index_h(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ bool efficiencies)
+{
+ return find_index_h(policy, target_freq, policy->min, policy->max, efficiencies);
+}
+
/* Find closest freq to target in a table in ascending order */
static inline int cpufreq_table_find_index_ac(struct cpufreq_policy *policy,
unsigned int target_freq,
@@ -1005,12 +1021,12 @@
return best;
}
-/* Works only on sorted freq-tables */
-static inline int cpufreq_table_find_index_c(struct cpufreq_policy *policy,
- unsigned int target_freq,
- bool efficiencies)
+static inline int find_index_c(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int min, unsigned int max,
+ bool efficiencies)
{
- target_freq = clamp_val(target_freq, policy->min, policy->max);
+ target_freq = clamp_val(target_freq, min, max);
if (policy->freq_table_sorted == CPUFREQ_TABLE_SORTED_ASCENDING)
return cpufreq_table_find_index_ac(policy, target_freq,
@@ -1020,7 +1036,17 @@
efficiencies);
}
-static inline bool cpufreq_is_in_limits(struct cpufreq_policy *policy, int idx)
+/* Works only on sorted freq-tables */
+static inline int cpufreq_table_find_index_c(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ bool efficiencies)
+{
+ return find_index_c(policy, target_freq, policy->min, policy->max, efficiencies);
+}
+
+static inline bool cpufreq_is_in_limits(struct cpufreq_policy *policy,
+ unsigned int min, unsigned int max,
+ int idx)
{
unsigned int freq;
@@ -1029,11 +1055,13 @@
freq = policy->freq_table[idx].frequency;
- return freq == clamp_val(freq, policy->min, policy->max);
+ return freq == clamp_val(freq, min, max);
}
static inline int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
unsigned int target_freq,
+ unsigned int min,
+ unsigned int max,
unsigned int relation)
{
bool efficiencies = policy->efficiencies_available &&
@@ -1044,29 +1072,26 @@
relation &= ~CPUFREQ_RELATION_E;
if (unlikely(policy->freq_table_sorted == CPUFREQ_TABLE_UNSORTED))
- return cpufreq_table_index_unsorted(policy, target_freq,
- relation);
+ return cpufreq_table_index_unsorted(policy, target_freq, min,
+ max, relation);
retry:
switch (relation) {
case CPUFREQ_RELATION_L:
- idx = cpufreq_table_find_index_l(policy, target_freq,
- efficiencies);
+ idx = find_index_l(policy, target_freq, min, max, efficiencies);
break;
case CPUFREQ_RELATION_H:
- idx = cpufreq_table_find_index_h(policy, target_freq,
- efficiencies);
+ idx = find_index_h(policy, target_freq, min, max, efficiencies);
break;
case CPUFREQ_RELATION_C:
- idx = cpufreq_table_find_index_c(policy, target_freq,
- efficiencies);
+ idx = find_index_c(policy, target_freq, min, max, efficiencies);
break;
default:
WARN_ON_ONCE(1);
return 0;
}
- /* Limit frequency index to honor policy->min/max */
- if (!cpufreq_is_in_limits(policy, idx) && efficiencies) {
+ /* Limit frequency index to honor min and max */
+ if (!cpufreq_is_in_limits(policy, min, max, idx) && efficiencies) {
efficiencies = false;
goto retry;
}
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