From: Viresh Kumar <[email protected]>
[ Upstream commit 70a59fde6e69d1d8579f84bf4555bfffb3ce452d ]
On some occasions cpufreq_verify_current_freq() schedules a work whose
callback is handle_update(), which further calls cpufreq_update_policy()
which may end up calling cpufreq_verify_current_freq() again.
On the other hand, when cpufreq_update_policy() is called from
handle_update(), the pointer to the cpufreq policy is already
available, but cpufreq_cpu_acquire() is still called to get it in
cpufreq_update_policy(), which should be avoided as well.
To fix these issues, create a new helper, refresh_frequency_limits(),
and make both handle_update() call it cpufreq_update_policy().
Signed-off-by: Viresh Kumar <[email protected]>
[ rjw: Rename reeval_frequency_limits() as refresh_frequency_limits() ]
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
drivers/cpufreq/cpufreq.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index e84bf0eb7239..876a4cb09de3 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1114,13 +1114,25 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cp
return ret;
}
+static void refresh_frequency_limits(struct cpufreq_policy *policy)
+{
+ struct cpufreq_policy new_policy = *policy;
+
+ pr_debug("updating policy for CPU %u\n", policy->cpu);
+
+ new_policy.min = policy->user_policy.min;
+ new_policy.max = policy->user_policy.max;
+
+ cpufreq_set_policy(policy, &new_policy);
+}
+
static void handle_update(struct work_struct *work)
{
struct cpufreq_policy *policy =
container_of(work, struct cpufreq_policy, update);
- unsigned int cpu = policy->cpu;
- pr_debug("handle_update for cpu %u called\n", cpu);
- cpufreq_update_policy(cpu);
+
+ pr_debug("handle_update for cpu %u called\n", policy->cpu);
+ refresh_frequency_limits(policy);
}
static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
@@ -2392,7 +2404,6 @@ int cpufreq_set_policy(struct cpufreq_policy *policy,
void cpufreq_update_policy(unsigned int cpu)
{
struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu);
- struct cpufreq_policy new_policy;
if (!policy)
return;
@@ -2405,12 +2416,7 @@ void cpufreq_update_policy(unsigned int cpu)
(cpufreq_suspended || WARN_ON(!cpufreq_update_current_freq(policy))))
goto unlock;
- pr_debug("updating policy for CPU %u\n", cpu);
- memcpy(&new_policy, policy, sizeof(*policy));
- new_policy.min = policy->user_policy.min;
- new_policy.max = policy->user_policy.max;
-
- cpufreq_set_policy(policy, &new_policy);
+ refresh_frequency_limits(policy);
unlock:
cpufreq_cpu_release(policy);
--
2.20.1
On 7/15/2019 3:45 PM, Sasha Levin wrote:
> From: Viresh Kumar <[email protected]>
>
> [ Upstream commit 70a59fde6e69d1d8579f84bf4555bfffb3ce452d ]
>
> On some occasions cpufreq_verify_current_freq() schedules a work whose
> callback is handle_update(), which further calls cpufreq_update_policy()
> which may end up calling cpufreq_verify_current_freq() again.
>
> On the other hand, when cpufreq_update_policy() is called from
> handle_update(), the pointer to the cpufreq policy is already
> available, but cpufreq_cpu_acquire() is still called to get it in
> cpufreq_update_policy(), which should be avoided as well.
>
> To fix these issues, create a new helper, refresh_frequency_limits(),
> and make both handle_update() call it cpufreq_update_policy().
>
> Signed-off-by: Viresh Kumar <[email protected]>
> [ rjw: Rename reeval_frequency_limits() as refresh_frequency_limits() ]
> [ rjw: Changelog ]
> Signed-off-by: Rafael J. Wysocki <[email protected]>
> Signed-off-by: Sasha Levin <[email protected]>
> ---
> drivers/cpufreq/cpufreq.c | 26 ++++++++++++++++----------
> 1 file changed, 16 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index e84bf0eb7239..876a4cb09de3 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -1114,13 +1114,25 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cp
> return ret;
> }
>
> +static void refresh_frequency_limits(struct cpufreq_policy *policy)
> +{
> + struct cpufreq_policy new_policy = *policy;
> +
> + pr_debug("updating policy for CPU %u\n", policy->cpu);
> +
> + new_policy.min = policy->user_policy.min;
> + new_policy.max = policy->user_policy.max;
> +
> + cpufreq_set_policy(policy, &new_policy);
> +}
> +
> static void handle_update(struct work_struct *work)
> {
> struct cpufreq_policy *policy =
> container_of(work, struct cpufreq_policy, update);
> - unsigned int cpu = policy->cpu;
> - pr_debug("handle_update for cpu %u called\n", cpu);
> - cpufreq_update_policy(cpu);
> +
> + pr_debug("handle_update for cpu %u called\n", policy->cpu);
> + refresh_frequency_limits(policy);
> }
>
> static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
> @@ -2392,7 +2404,6 @@ int cpufreq_set_policy(struct cpufreq_policy *policy,
> void cpufreq_update_policy(unsigned int cpu)
> {
> struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu);
> - struct cpufreq_policy new_policy;
>
> if (!policy)
> return;
> @@ -2405,12 +2416,7 @@ void cpufreq_update_policy(unsigned int cpu)
> (cpufreq_suspended || WARN_ON(!cpufreq_update_current_freq(policy))))
> goto unlock;
>
> - pr_debug("updating policy for CPU %u\n", cpu);
> - memcpy(&new_policy, policy, sizeof(*policy));
> - new_policy.min = policy->user_policy.min;
> - new_policy.max = policy->user_policy.max;
> -
> - cpufreq_set_policy(policy, &new_policy);
> + refresh_frequency_limits(policy);
>
> unlock:
> cpufreq_cpu_release(policy);
I don't think this is suitable for -stable.
On Tue, Jul 16, 2019 at 11:25:00AM +0200, Rafael J. Wysocki wrote:
>On 7/15/2019 3:45 PM, Sasha Levin wrote:
>>From: Viresh Kumar <[email protected]>
>>
>>[ Upstream commit 70a59fde6e69d1d8579f84bf4555bfffb3ce452d ]
>>
>>On some occasions cpufreq_verify_current_freq() schedules a work whose
>>callback is handle_update(), which further calls cpufreq_update_policy()
>>which may end up calling cpufreq_verify_current_freq() again.
>>
>>On the other hand, when cpufreq_update_policy() is called from
>>handle_update(), the pointer to the cpufreq policy is already
>>available, but cpufreq_cpu_acquire() is still called to get it in
>>cpufreq_update_policy(), which should be avoided as well.
>>
>>To fix these issues, create a new helper, refresh_frequency_limits(),
>>and make both handle_update() call it cpufreq_update_policy().
>>
>>Signed-off-by: Viresh Kumar <[email protected]>
>>[ rjw: Rename reeval_frequency_limits() as refresh_frequency_limits() ]
>>[ rjw: Changelog ]
>>Signed-off-by: Rafael J. Wysocki <[email protected]>
>>Signed-off-by: Sasha Levin <[email protected]>
>>---
>> drivers/cpufreq/cpufreq.c | 26 ++++++++++++++++----------
>> 1 file changed, 16 insertions(+), 10 deletions(-)
>>
>>diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
>>index e84bf0eb7239..876a4cb09de3 100644
>>--- a/drivers/cpufreq/cpufreq.c
>>+++ b/drivers/cpufreq/cpufreq.c
>>@@ -1114,13 +1114,25 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cp
>> return ret;
>> }
>>+static void refresh_frequency_limits(struct cpufreq_policy *policy)
>>+{
>>+ struct cpufreq_policy new_policy = *policy;
>>+
>>+ pr_debug("updating policy for CPU %u\n", policy->cpu);
>>+
>>+ new_policy.min = policy->user_policy.min;
>>+ new_policy.max = policy->user_policy.max;
>>+
>>+ cpufreq_set_policy(policy, &new_policy);
>>+}
>>+
>> static void handle_update(struct work_struct *work)
>> {
>> struct cpufreq_policy *policy =
>> container_of(work, struct cpufreq_policy, update);
>>- unsigned int cpu = policy->cpu;
>>- pr_debug("handle_update for cpu %u called\n", cpu);
>>- cpufreq_update_policy(cpu);
>>+
>>+ pr_debug("handle_update for cpu %u called\n", policy->cpu);
>>+ refresh_frequency_limits(policy);
>> }
>> static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
>>@@ -2392,7 +2404,6 @@ int cpufreq_set_policy(struct cpufreq_policy *policy,
>> void cpufreq_update_policy(unsigned int cpu)
>> {
>> struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu);
>>- struct cpufreq_policy new_policy;
>> if (!policy)
>> return;
>>@@ -2405,12 +2416,7 @@ void cpufreq_update_policy(unsigned int cpu)
>> (cpufreq_suspended || WARN_ON(!cpufreq_update_current_freq(policy))))
>> goto unlock;
>>- pr_debug("updating policy for CPU %u\n", cpu);
>>- memcpy(&new_policy, policy, sizeof(*policy));
>>- new_policy.min = policy->user_policy.min;
>>- new_policy.max = policy->user_policy.max;
>>-
>>- cpufreq_set_policy(policy, &new_policy);
>>+ refresh_frequency_limits(policy);
>> unlock:
>> cpufreq_cpu_release(policy);
>
>I don't think this is suitable for -stable.
I've dropped it, thanks!
--
Thanks,
Sasha