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| author | Ulf Hansson <ulf.hansson@linaro.org> | 2020-09-30 13:20:23 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2020-09-30 17:42:43 +0200 |
| commit | 1a67b9263e06688d7f683714cace8dcc203f8c55 (patch) | |
| tree | a2ac2f4290092af09c08cc0c36bd22a339c506ea | |
| parent | eac53b3e304a8354dc2a2f38e60e712d0e110ef6 (diff) | |
| download | linux-1a67b9263e06688d7f683714cace8dcc203f8c55.tar.gz | |
ARM: imx6q: Fixup RCU usage for cpuidle
The commit eb1f00237aca ("lockdep,trace: Expose tracepoints"), started to
expose us for tracepoints. For imx6q cpuidle, this leads to an RCU splat
according to below.
[6.870684] [<c0db7690>] (_raw_spin_lock) from [<c011f6a4>] (imx6q_enter_wait+0x18/0x9c)
[6.878846] [<c011f6a4>] (imx6q_enter_wait) from [<c09abfb0>] (cpuidle_enter_state+0x168/0x5e4)
To fix the problem, let's assign the corresponding idlestate->flags the
CPUIDLE_FLAG_RCU_IDLE bit, which enables us to call rcu_idle_enter|exit()
at the proper point.
Reported-by: Dong Aisheng <aisheng.dong@nxp.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | arch/arm/mach-imx/cpuidle-imx6q.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/arm/mach-imx/cpuidle-imx6q.c b/arch/arm/mach-imx/cpuidle-imx6q.c index 24dd5bbe60e43c..094337dc1bc7e3 100644 --- a/arch/arm/mach-imx/cpuidle-imx6q.c +++ b/arch/arm/mach-imx/cpuidle-imx6q.c @@ -24,7 +24,9 @@ static int imx6q_enter_wait(struct cpuidle_device *dev, imx6_set_lpm(WAIT_UNCLOCKED); raw_spin_unlock(&cpuidle_lock); + rcu_idle_enter(); cpu_do_idle(); + rcu_idle_exit(); raw_spin_lock(&cpuidle_lock); if (num_idle_cpus-- == num_online_cpus()) @@ -44,7 +46,7 @@ static struct cpuidle_driver imx6q_cpuidle_driver = { { .exit_latency = 50, .target_residency = 75, - .flags = CPUIDLE_FLAG_TIMER_STOP, + .flags = CPUIDLE_FLAG_TIMER_STOP | CPUIDLE_FLAG_RCU_IDLE, .enter = imx6q_enter_wait, .name = "WAIT", .desc = "Clock off", |