From fc7d17551f776fda243493ce59894c1eec2a339f Mon Sep 17 00:00:00 2001 From: Zhang Rui Date: Mon, 28 Sep 2020 11:33:42 +0800 Subject: [PATCH 1/3] cpufreq: intel_pstate: Fix missing return statement Fix missing return statement when writing "off" to intel_pstate status sysfs I/F. Fixes: 55671ea3257a ("cpufreq: intel_pstate: Free memory only when turning off") Signed-off-by: Zhang Rui Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/intel_pstate.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index a827b000ef51..9a515c460a00 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -2781,6 +2781,7 @@ static int intel_pstate_update_status(const char *buf, size_t size) cpufreq_unregister_driver(intel_pstate_driver); intel_pstate_driver_cleanup(); + return 0; } if (size == 6 && !strncmp(buf, "active", size)) { From eac53b3e304a8354dc2a2f38e60e712d0e110ef6 Mon Sep 17 00:00:00 2001 From: Yoann Congal Date: Tue, 29 Sep 2020 22:41:58 +0200 Subject: [PATCH 2/3] Documentation: PM: Fix a reStructuredText syntax error Fix a reStructuredText syntax error in the cpuidle PM admin-guide documentation: the ``...'' quotation marks are parsed as partial ''...'' reStructuredText markup and break the output formatting. This change them to "...". Signed-off-by: Yoann Congal Signed-off-by: Rafael J. Wysocki --- Documentation/admin-guide/pm/cpuidle.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Documentation/admin-guide/pm/cpuidle.rst b/Documentation/admin-guide/pm/cpuidle.rst index a96a423e3779..6ebe163f9dfe 100644 --- a/Documentation/admin-guide/pm/cpuidle.rst +++ b/Documentation/admin-guide/pm/cpuidle.rst @@ -690,7 +690,7 @@ which of the two parameters is added to the kernel command line. In the instruction of the CPUs (which, as a rule, suspends the execution of the program and causes the hardware to attempt to enter the shallowest available idle state) for this purpose, and if ``idle=poll`` is used, idle CPUs will execute a -more or less ``lightweight'' sequence of instructions in a tight loop. [Note +more or less "lightweight" sequence of instructions in a tight loop. [Note that using ``idle=poll`` is somewhat drastic in many cases, as preventing idle CPUs from saving almost any energy at all may not be the only effect of it. For example, on Intel hardware it effectively prevents CPUs from using From 1a67b9263e06688d7f683714cace8dcc203f8c55 Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Wed, 30 Sep 2020 13:20:23 +0200 Subject: [PATCH 3/3] 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] [] (_raw_spin_lock) from [] (imx6q_enter_wait+0x18/0x9c) [6.878846] [] (imx6q_enter_wait) from [] (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 Suggested-by: Peter Zijlstra Signed-off-by: Ulf Hansson Acked-by: Peter Zijlstra (Intel) Signed-off-by: Rafael J. Wysocki --- arch/arm/mach-imx/cpuidle-imx6q.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) 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",