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 inefficient frequency. Add additional check to ensure that resolving a frequency will respect policy->min/max.
Fixes: 1f39fa0dccff ("cpufreq: Introducing CPUFREQ_RELATION_E") Signed-off-by: Shivnandan Kumar quic_kshivnan@quicinc.com --- include/linux/cpufreq.h | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index afda5f24d3dd..42d98b576a36 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -1021,6 +1021,19 @@ static inline int cpufreq_table_find_index_c(struct cpufreq_policy *policy, efficiencies); }
+static inline bool cpufreq_table_index_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) @@ -1054,7 +1067,10 @@ 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_table_index_is_in_limits(policy, idx) && efficiencies) { efficiencies = false; goto retry; }
Hi,
Thanks for your patch.
FYI: kernel test robot notices the stable kernel rule is not satisfied.
The check is based on https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html#opti...
Rule: add the tag "Cc: stable@vger.kernel.org" in the sign-off area to have the patch automatically included in the stable tree. Subject: [PATCH] cpufreq: Limit resolving a frequency to policy min/max Link: https://lore.kernel.org/stable/20240222083515.1065025-1-quic_kshivnan%40quic...
On Thu, Feb 22, 2024 at 9:35 AM Shivnandan Kumar quic_kshivnan@quicinc.com wrote:
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 inefficient frequency. Add additional check to ensure that resolving a frequency will respect policy->min/max.
Fixes: 1f39fa0dccff ("cpufreq: Introducing CPUFREQ_RELATION_E") Signed-off-by: Shivnandan Kumar quic_kshivnan@quicinc.com
include/linux/cpufreq.h | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index afda5f24d3dd..42d98b576a36 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -1021,6 +1021,19 @@ static inline int cpufreq_table_find_index_c(struct cpufreq_policy *policy, efficiencies); }
+static inline bool cpufreq_table_index_is_in_limits(struct cpufreq_policy *policy,
int idx)
This is not really about the index only, but about the frequency at that index too, so I'd call the function differently.
+{
unsigned int freq;if (idx < 0)return false;freq = policy->freq_table[idx].frequency;return (freq == clamp_val(freq, policy->min, policy->max));
Redundant outer parens.
+}
static inline int cpufreq_frequency_table_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation) @@ -1054,7 +1067,10 @@ 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*/
This comment need not be multi-line.
if (!cpufreq_table_index_is_in_limits(policy, idx) && efficiencies) { efficiencies = false; goto retry; }--
Thanks!
Hi Rafael,
Thanks for reviewing the change.
On 2/23/2024 12:52 AM, Rafael J. Wysocki wrote:
On Thu, Feb 22, 2024 at 9:35 AM Shivnandan Kumar quic_kshivnan@quicinc.com wrote:
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 inefficient frequency. Add additional check to ensure that resolving a frequency will respect policy->min/max.
Fixes: 1f39fa0dccff ("cpufreq: Introducing CPUFREQ_RELATION_E") Signed-off-by: Shivnandan Kumar quic_kshivnan@quicinc.com
include/linux/cpufreq.h | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index afda5f24d3dd..42d98b576a36 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -1021,6 +1021,19 @@ static inline int cpufreq_table_find_index_c(struct cpufreq_policy *policy, efficiencies); }
+static inline bool cpufreq_table_index_is_in_limits(struct cpufreq_policy *policy,
int idx)This is not really about the index only, but about the frequency at that index too, so I'd call the function differently.
ACK
+{
unsigned int freq;if (idx < 0)return false;freq = policy->freq_table[idx].frequency;return (freq == clamp_val(freq, policy->min, policy->max));Redundant outer parens.
ACK
+}
- static inline int cpufreq_frequency_table_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation)
@@ -1054,7 +1067,10 @@ 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*/This comment need not be multi-line.
ACK I will make the changes in next patch set.
Thanks Shivnandan
if (!cpufreq_table_index_is_in_limits(policy, idx) && efficiencies) { efficiencies = false; goto retry; }--
Thanks!
linux-stable-mirror@lists.linaro.org
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kernel test robot -
Rafael J. Wysocki -
Shivnandan Kumar