From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Pavel Machek <pavel@ucw.cz>, Len Brown <len.brown@intel.com>
Subject: [PATCH RFC] suspend: Prevent might sleep splats
Date: Thu, 24 May 2018 16:24:26 +0200 [thread overview]
Message-ID: <20180524142426.jeyszeqdrjvb3tob@linutronix.de> (raw)
From: Thomas Gleixner <tglx@linutronix.de>
timekeeping suspend/resume calls read_persistent_clock() which takes
rtc_lock. That results in might sleep warnings because at that point
we run with interrupts disabled.
We cannot convert rtc_lock to a raw spinlock as that would trigger
other might sleep warnings.
As a workaround we disable the might sleep warnings by setting
system_state to SYSTEM_SUSPEND before calling sysdev_suspend() and
restoring it to SYSTEM_RUNNING afer sysdev_resume().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
include/linux/kernel.h | 1 +
kernel/power/hibernate.c | 7 +++++++
kernel/power/suspend.c | 4 ++++
3 files changed, 12 insertions(+)
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -532,6 +532,7 @@ extern enum system_states {
SYSTEM_HALT,
SYSTEM_POWER_OFF,
SYSTEM_RESTART,
+ SYSTEM_SUSPEND,
} system_state;
#define TAINT_PROPRIETARY_MODULE 0
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -287,6 +287,8 @@ static int create_image(int platform_mod
local_irq_disable();
+ system_state = SYSTEM_SUSPEND;
+
error = syscore_suspend();
if (error) {
pr_err("Some system devices failed to power down, aborting hibernation\n");
@@ -317,6 +319,7 @@ static int create_image(int platform_mod
syscore_resume();
Enable_irqs:
+ system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
@@ -445,6 +448,7 @@ static int resume_target_kernel(bool pla
goto Enable_cpus;
local_irq_disable();
+ system_state = SYSTEM_SUSPEND;
error = syscore_suspend();
if (error)
@@ -478,6 +482,7 @@ static int resume_target_kernel(bool pla
syscore_resume();
Enable_irqs:
+ system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
@@ -563,6 +568,7 @@ int hibernation_platform_enter(void)
goto Enable_cpus;
local_irq_disable();
+ system_state = SYSTEM_SUSPEND;
syscore_suspend();
if (pm_wakeup_pending()) {
error = -EAGAIN;
@@ -575,6 +581,7 @@ int hibernation_platform_enter(void)
Power_up:
syscore_resume();
+ system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -428,6 +428,8 @@ static int suspend_enter(suspend_state_t
arch_suspend_disable_irqs();
BUG_ON(!irqs_disabled());
+ system_state = SYSTEM_SUSPEND;
+
error = syscore_suspend();
if (!error) {
*wakeup = pm_wakeup_pending();
@@ -443,6 +445,8 @@ static int suspend_enter(suspend_state_t
syscore_resume();
}
+ system_state = SYSTEM_RUNNING;
+
arch_suspend_enable_irqs();
BUG_ON(irqs_disabled());
next reply other threads:[~2018-05-24 14:24 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-24 14:24 Sebastian Andrzej Siewior [this message]
2018-05-24 15:07 ` [PATCH RFC] suspend: Prevent might sleep splats Rafael J. Wysocki
2018-05-24 15:45 ` Sebastian Andrzej Siewior
2018-05-24 15:57 ` Rafael J. Wysocki
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