[PATCH 5.15 045/177] cpufreq: qcom-hw: fix the race between LMH worker and cpuhp

Greg Kroah-Hartman
2022-05-04T17:18:23Z

From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

[ Upstream commit 5e4f009da6be563984ba4db4ef4f32529e9aeb90 ]

The driver would disable the worker when cpu is being put offline, but
it happens closer to the end of cpufreq_offline(). The function
qcom_lmh_dcvs_poll() can be running in parallel with this, when
policy->cpus already has been updated. Read policy->related_cpus
instead.

[ 37.122433] ------------[ cut here ]------------
[ 37.127225] WARNING: CPU: 0 PID: 187 at drivers/base/arch_topology.c:180 topology_update_thermal_pressure+0xec/0x100
[ 37.138098] Modules linked in:
[ 37.141279] CPU: 0 PID: 187 Comm: kworker/0:3 Tainted: G S 5.17.0-rc6-00389-g37c83d0b8710-dirty #713
[ 37.158306] Workqueue: events qcom_lmh_dcvs_poll
[ 37.163095] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 37.170278] pc : topology_update_thermal_pressure+0xec/0x100
[ 37.176131] lr : topology_update_thermal_pressure+0x20/0x100
[ 37.181977] sp : ffff800009b6bce0
[ 37.185402] x29: ffff800009b6bce0 x28: ffffd87abe92b000 x27: ffff04bd7292e205
[ 37.192792] x26: ffffd87abe930af8 x25: ffffd87abe94e4c8 x24: 0000000000000000
[ 37.200180] x23: ffff04bb01177018 x22: ffff04bb011770c0 x21: ffff04bb01177000
[ 37.207567] x20: ffff04bb0a419000 x19: 00000000000c4e00 x18: 0000000000000000
[ 37.214954] x17: 000000040044ffff x16: 004000b2b5503510 x15: 0000006aaa1326d2
[ 37.222333] x14: 0000000000000232 x13: 0000000000000001 x12: 0000000000000040
[ 37.229718] x11: ffff04bb00400000 x10: 968f57bd39f701c8 x9 : ffff04bb0acc8674
[ 37.237095] x8 : fefefefefefefeff x7 : 0000000000000018 x6 : ffffd87abd90092c
[ 37.244478] x5 : 0000000000000016 x4 : 0000000000000000 x3 : 0000000000000100
[ 37.251852] x2 : ffff04bb0a419020 x1 : 0000000000000100 x0 : 0000000000000100
[ 37.259235] Call trace:
[ 37.261771] topology_update_thermal_pressure+0xec/0x100
[ 37.267266] qcom_lmh_dcvs_poll+0xbc/0x154
[ 37.271505] process_one_work+0x288/0x69c
[ 37.275654] worker_thread+0x74/0x470
[ 37.279450] kthread+0xfc/0x100
[ 37.282712] ret_from_fork+0x10/0x20
[ 37.286417] irq event stamp: 74
[ 37.289664] hardirqs last enabled at (73): [<ffffd87abdd78af4>] _raw_spin_unlock_irq+0x44/0x80
[ 37.298632] hardirqs last disabled at (74): [<ffffd87abdd71fc0>] __schedule+0x710/0xa10
[ 37.306885] softirqs last enabled at (58): [<ffffd87abcc90410>] _stext+0x410/0x588
[ 37.314778] softirqs last disabled at (51): [<ffffd87abcd1bf68>] __irq_exit_rcu+0x158/0x174
[ 37.323386] ---[ end trace 0000000000000000 ]---

Fixes: 275157b367f4 ("cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/cpufreq/qcom-cpufreq-hw.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index 35d93361fda1..dfe72d82858f 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -277,7 +277,7 @@ static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data)
{
unsigned long max_capacity, capacity, freq_hz, throttled_freq;
struct cpufreq_policy *policy = data->policy;
- int cpu = cpumask_first(policy->cpus);
+ int cpu = cpumask_first(policy->related_cpus);
struct device *dev = get_cpu_device(cpu);
struct dev_pm_opp *opp;
unsigned int freq;
--
2.35.1