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Message-Id: <1464842009-21789-5-git-send-email-dbasehore@chromium.org>
Date: Wed, 1 Jun 2016 21:33:28 -0700
From: dbasehore@...omium.org
To: linux-kernel@...r.kernel.org
Cc: dbasehore@...omium.org, linux-pm@...r.kernel.org,
rjw@...ysocki.net, pavel@....cz, len.brown@...el.com,
tglx@...utronix.de
Subject: [PATCH 4/5] freeze: Add error reporting
From: Derek Basehore <dbasehore@...omium.org>
This adds error reporting for cpuidle to freeze so suspend-to-idle can
report errors when the CPU/SoC is unable to idle properly. Freeze will
abort when an error is encounted.
Signed-off-by: Derek Basehore <dbasehore@...omium.org>
---
drivers/acpi/processor_idle.c | 10 ++++++----
drivers/cpuidle/cpuidle.c | 31 ++++++++++++++++++++++++++-----
drivers/idle/intel_idle.c | 8 +++++---
include/linux/cpuidle.h | 10 ++++++----
kernel/power/suspend.c | 11 +++++++----
5 files changed, 50 insertions(+), 20 deletions(-)
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 444e374..a959b32 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -783,8 +783,8 @@ static int acpi_idle_enter(struct cpuidle_device *dev,
return index;
}
-static void acpi_idle_enter_freeze(struct cpuidle_device *dev,
- struct cpuidle_driver *drv, int index)
+static int acpi_idle_enter_freeze(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index)
{
struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
@@ -792,16 +792,18 @@ static void acpi_idle_enter_freeze(struct cpuidle_device *dev,
struct acpi_processor *pr = __this_cpu_read(processors);
if (unlikely(!pr))
- return;
+ return 0;
if (pr->flags.bm_check) {
acpi_idle_enter_bm(pr, cx, false);
- return;
+ return 0;
} else {
ACPI_FLUSH_CPU_CACHE();
}
}
acpi_idle_do_entry(cx);
+
+ return 0;
}
struct cpuidle_driver acpi_idle_driver = {
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index a4d0059..2664a6c 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -34,6 +34,7 @@ LIST_HEAD(cpuidle_detected_devices);
static int enabled_devices;
static int off __read_mostly;
static int initialized __read_mostly;
+static int cpuidle_freeze_error;
int cpuidle_disabled(void)
{
@@ -109,9 +110,11 @@ int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
return find_deepest_state(drv, dev, UINT_MAX, 0, false);
}
-static void enter_freeze_proper(struct cpuidle_driver *drv,
+static int enter_freeze_proper(struct cpuidle_driver *drv,
struct cpuidle_device *dev, int index)
{
+ int ret;
+
/*
* trace_suspend_resume() called by tick_freeze() for the last CPU
* executing it contains RCU usage regarded as invalid in the idle
@@ -124,7 +127,7 @@ static void enter_freeze_proper(struct cpuidle_driver *drv,
* suspended is generally unsafe.
*/
stop_critical_timings();
- drv->states[index].enter_freeze(dev, drv, index);
+ ret = drv->states[index].enter_freeze(dev, drv, index);
WARN_ON(!irqs_disabled());
/*
* timekeeping_resume() that will be called by tick_unfreeze() for the
@@ -133,6 +136,7 @@ static void enter_freeze_proper(struct cpuidle_driver *drv,
*/
RCU_NONIDLE(tick_unfreeze());
start_critical_timings();
+ return ret;
}
/**
@@ -145,7 +149,7 @@ static void enter_freeze_proper(struct cpuidle_driver *drv,
*/
int cpuidle_enter_freeze(struct cpuidle_driver *drv, struct cpuidle_device *dev)
{
- int index;
+ int index, ret = 0;
/*
* Find the deepest state with ->enter_freeze present, which guarantees
@@ -153,8 +157,13 @@ int cpuidle_enter_freeze(struct cpuidle_driver *drv, struct cpuidle_device *dev)
* be frozen safely.
*/
index = find_deepest_state(drv, dev, UINT_MAX, 0, true);
- if (index > 0)
- enter_freeze_proper(drv, dev, index);
+ if (index >= 0)
+ ret = enter_freeze_proper(drv, dev, index);
+
+ if (ret < 0) {
+ cpuidle_freeze_error = ret;
+ freeze_wake();
+ }
return index;
}
@@ -353,6 +362,18 @@ void cpuidle_resume(void)
mutex_unlock(&cpuidle_lock);
}
+void cpuidle_prepare_freeze(void)
+{
+ cpuidle_freeze_error = 0;
+ cpuidle_resume();
+}
+
+int cpuidle_complete_freeze(void)
+{
+ cpuidle_pause();
+ return cpuidle_freeze_error;
+}
+
/**
* cpuidle_enable_device - enables idle PM for a CPU
* @dev: the CPU
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index c966492..98565de 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -97,8 +97,8 @@ static const struct idle_cpu *icpu;
static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
static int intel_idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index);
-static void intel_idle_freeze(struct cpuidle_device *dev,
- struct cpuidle_driver *drv, int index);
+static int intel_idle_freeze(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index);
static int intel_idle_cpu_init(int cpu);
static struct cpuidle_state *cpuidle_state_table;
@@ -870,13 +870,15 @@ static int intel_idle(struct cpuidle_device *dev,
* @drv: cpuidle driver
* @index: state index
*/
-static void intel_idle_freeze(struct cpuidle_device *dev,
+static int intel_idle_freeze(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index)
{
unsigned long ecx = 1; /* break on interrupt flag */
unsigned long eax = flg2MWAIT(drv->states[index].flags);
mwait_idle_with_hints(eax, ecx);
+
+ return 0;
}
static void __setup_broadcast_timer(void *arg)
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index 786ad32..27f6b11 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -54,11 +54,11 @@ struct cpuidle_state {
/*
* CPUs execute ->enter_freeze with the local tick or entire timekeeping
* suspended, so it must not re-enable interrupts at any point (even
- * temporarily) or attempt to change states of clock event devices.
+ * temporarily). Returns 0 on success and non-zero if an error occurred.
*/
- void (*enter_freeze) (struct cpuidle_device *dev,
- struct cpuidle_driver *drv,
- int index);
+ int (*enter_freeze) (struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index);
};
/* Idle State Flags */
@@ -147,6 +147,8 @@ extern void cpuidle_pause_and_lock(void);
extern void cpuidle_resume_and_unlock(void);
extern void cpuidle_pause(void);
extern void cpuidle_resume(void);
+extern void cpuidle_prepare_freeze(void);
+extern int cpuidle_complete_freeze(void);
extern int cpuidle_enable_device(struct cpuidle_device *dev);
extern void cpuidle_disable_device(struct cpuidle_device *dev);
extern int cpuidle_play_dead(void);
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 5b70d64..419154b 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -57,8 +57,10 @@ static void freeze_begin(void)
suspend_freeze_state = FREEZE_STATE_NONE;
}
-static void freeze_enter(void)
+static int freeze_enter(void)
{
+ int error = 0;
+
spin_lock_irq(&suspend_freeze_lock);
if (pm_wakeup_pending())
goto out;
@@ -67,7 +69,7 @@ static void freeze_enter(void)
spin_unlock_irq(&suspend_freeze_lock);
get_online_cpus();
- cpuidle_resume();
+ cpuidle_prepare_freeze();
/* Push all the CPUs into the idle loop. */
wake_up_all_idle_cpus();
@@ -77,7 +79,7 @@ static void freeze_enter(void)
suspend_freeze_state == FREEZE_STATE_WAKE);
pr_debug("PM: resume from suspend-to-idle\n");
- cpuidle_pause();
+ error = cpuidle_complete_freeze();
put_online_cpus();
spin_lock_irq(&suspend_freeze_lock);
@@ -85,6 +87,7 @@ static void freeze_enter(void)
out:
suspend_freeze_state = FREEZE_STATE_NONE;
spin_unlock_irq(&suspend_freeze_lock);
+ return error;
}
void freeze_wake(void)
@@ -347,7 +350,7 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
*/
if (state == PM_SUSPEND_FREEZE) {
trace_suspend_resume(TPS("machine_suspend"), state, true);
- freeze_enter();
+ error = freeze_enter();
trace_suspend_resume(TPS("machine_suspend"), state, false);
goto Platform_wake;
}
--
2.8.0.rc3.226.g39d4020
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