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authorUlf Hansson <ulf.hansson@linaro.org>2020-09-30 13:20:23 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2020-09-30 17:42:43 +0200
commit1a67b9263e06688d7f683714cace8dcc203f8c55 (patch)
treea2ac2f4290092af09c08cc0c36bd22a339c506ea
parenteac53b3e304a8354dc2a2f38e60e712d0e110ef6 (diff)
downloadlinux-1a67b9263e06688d7f683714cace8dcc203f8c55.tar.bz2
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.c4
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 24dd5bbe60e4..094337dc1bc7 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",