[PATCH] cpufreq: Send CPUFREQ_CREATE_POLICY notification after the perf domain creation.

From: Vincent Wang
Date: Sun Jan 15 2023 - 06:03:13 EST


From: Vincent Wang <vincentwang3@xxxxxxxxxx>

We found the following issue during kernel boot on android phone:

[ 1.325272][ T1] cpu cpu0: EM: created perf domain
[ 1.329317][ T1] cpu cpu4: EM: created perf domain
[ 1.337597][ T76] pd_init: no EM found for CPU7
[ 1.350849][ T1] cpu cpu7: EM: created perf domain

pd init for cluster2 is executed in a kworker thread and
is earlier than the perf domain creation for cluster2.

pd_init() is called from the cpufreq notification of
CPUFREQ_CREATE_POLICY in cpufreq_online(), which is earlier
than that cpufreq_driver->register_em() is called.

To avoid this issue, cpufreq notification should be sent after
the perf domain creation.

Signed-off-by: Vincent Wang <vincentwang3@xxxxxxxxxx>
---
drivers/cpufreq/cpufreq.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 7e56a42750ea..9e67df4fc334 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1506,6 +1506,9 @@ static int cpufreq_online(unsigned int cpu)
*/
if (cpufreq_driver->register_em)
cpufreq_driver->register_em(policy);
+
+ blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+ CPUFREQ_CREATE_POLICY, policy);
}

ret = cpufreq_init_policy(policy);
--
2.25.1