From dc0075ba7f387fe4c48a8c674b11ab6f374a6acc Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 4 Feb 2022 18:31:02 +0100 Subject: ACPI: PM: s2idle: Cancel wakeup before dispatching EC GPE Commit 4a9af6cac050 ("ACPI: EC: Rework flushing of EC work while suspended to idle") made acpi_ec_dispatch_gpe() check pm_wakeup_pending(), but that is before canceling the SCI wakeup, so pm_wakeup_pending() is always true. This causes the loop in acpi_ec_dispatch_gpe() to always terminate after one iteration which may not be correct. Address this issue by canceling the SCI wakeup earlier, from acpi_ec_dispatch_gpe() itself. Fixes: 4a9af6cac050 ("ACPI: EC: Rework flushing of EC work while suspended to idle") Signed-off-by: Rafael J. Wysocki --- drivers/acpi/sleep.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) (limited to 'drivers/acpi/sleep.c') diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c index a60ff5dfed3a..fac7c9d4c9a1 100644 --- a/drivers/acpi/sleep.c +++ b/drivers/acpi/sleep.c @@ -736,21 +736,15 @@ bool acpi_s2idle_wake(void) return true; } - /* Check non-EC GPE wakeups and dispatch the EC GPE. */ + /* + * Check non-EC GPE wakeups and if there are none, cancel the + * SCI-related wakeup and dispatch the EC GPE. + */ if (acpi_ec_dispatch_gpe()) { pm_pr_dbg("ACPI non-EC GPE wakeup\n"); return true; } - /* - * Cancel the SCI wakeup and process all pending events in case - * there are any wakeup ones in there. - * - * Note that if any non-EC GPEs are active at this point, the - * SCI will retrigger after the rearming below, so no events - * should be missed by canceling the wakeup here. - */ - pm_system_cancel_wakeup(); acpi_os_wait_events_complete(); /* -- cgit v1.2.3 From cb1f65c1e1424a4b5e4a86da8aa3b8fd8459c8ec Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 4 Feb 2022 18:35:22 +0100 Subject: PM: s2idle: ACPI: Fix wakeup interrupts handling After commit e3728b50cd9b ("ACPI: PM: s2idle: Avoid possible race related to the EC GPE") wakeup interrupts occurring immediately after the one discarded by acpi_s2idle_wake() may be missed. Moreover, if the SCI triggers again immediately after the rearming in acpi_s2idle_wake(), that wakeup may be missed too. The problem is that pm_system_irq_wakeup() only calls pm_system_wakeup() when pm_wakeup_irq is 0, but that's not the case any more after the interrupt causing acpi_s2idle_wake() to run until pm_wakeup_irq is cleared by the pm_wakeup_clear() call in s2idle_loop(). However, there may be wakeup interrupts occurring in that time frame and if that happens, they will be missed. To address that issue first move the clearing of pm_wakeup_irq to the point at which it is known that the interrupt causing acpi_s2idle_wake() to tun will be discarded, before rearming the SCI for wakeup. Moreover, because that only reduces the size of the time window in which the issue may manifest itself, allow pm_system_irq_wakeup() to register two second wakeup interrupts in a row and, when discarding the first one, replace it with the second one. [Of course, this assumes that only one wakeup interrupt can be discarded in one go, but currently that is the case and I am not aware of any plans to change that.] Fixes: e3728b50cd9b ("ACPI: PM: s2idle: Avoid possible race related to the EC GPE") Cc: 5.4+ # 5.4+ Signed-off-by: Rafael J. Wysocki --- drivers/acpi/sleep.c | 1 + drivers/base/power/wakeup.c | 41 ++++++++++++++++++++++++++++++++++------- include/linux/suspend.h | 4 ++-- kernel/power/main.c | 5 ++++- kernel/power/process.c | 2 +- kernel/power/suspend.c | 2 -- 6 files changed, 42 insertions(+), 13 deletions(-) (limited to 'drivers/acpi/sleep.c') diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c index fac7c9d4c9a1..d4fbea91ab6b 100644 --- a/drivers/acpi/sleep.c +++ b/drivers/acpi/sleep.c @@ -758,6 +758,7 @@ bool acpi_s2idle_wake(void) return true; } + pm_wakeup_clear(acpi_sci_irq); rearm_wake_irq(acpi_sci_irq); } diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c index 99bda0da23a8..8666590201c9 100644 --- a/drivers/base/power/wakeup.c +++ b/drivers/base/power/wakeup.c @@ -34,7 +34,8 @@ suspend_state_t pm_suspend_target_state; bool events_check_enabled __read_mostly; /* First wakeup IRQ seen by the kernel in the last cycle. */ -unsigned int pm_wakeup_irq __read_mostly; +static unsigned int wakeup_irq[2] __read_mostly; +static DEFINE_RAW_SPINLOCK(wakeup_irq_lock); /* If greater than 0 and the system is suspending, terminate the suspend. */ static atomic_t pm_abort_suspend __read_mostly; @@ -942,19 +943,45 @@ void pm_system_cancel_wakeup(void) atomic_dec_if_positive(&pm_abort_suspend); } -void pm_wakeup_clear(bool reset) +void pm_wakeup_clear(unsigned int irq_number) { - pm_wakeup_irq = 0; - if (reset) + raw_spin_lock_irq(&wakeup_irq_lock); + + if (irq_number && wakeup_irq[0] == irq_number) + wakeup_irq[0] = wakeup_irq[1]; + else + wakeup_irq[0] = 0; + + wakeup_irq[1] = 0; + + raw_spin_unlock_irq(&wakeup_irq_lock); + + if (!irq_number) atomic_set(&pm_abort_suspend, 0); } void pm_system_irq_wakeup(unsigned int irq_number) { - if (pm_wakeup_irq == 0) { - pm_wakeup_irq = irq_number; + unsigned long flags; + + raw_spin_lock_irqsave(&wakeup_irq_lock, flags); + + if (wakeup_irq[0] == 0) + wakeup_irq[0] = irq_number; + else if (wakeup_irq[1] == 0) + wakeup_irq[1] = irq_number; + else + irq_number = 0; + + raw_spin_unlock_irqrestore(&wakeup_irq_lock, flags); + + if (irq_number) pm_system_wakeup(); - } +} + +unsigned int pm_wakeup_irq(void) +{ + return wakeup_irq[0]; } /** diff --git a/include/linux/suspend.h b/include/linux/suspend.h index 3e8ecdebe601..300273ff40cc 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -497,14 +497,14 @@ extern void ksys_sync_helper(void); /* drivers/base/power/wakeup.c */ extern bool events_check_enabled; -extern unsigned int pm_wakeup_irq; extern suspend_state_t pm_suspend_target_state; extern bool pm_wakeup_pending(void); extern void pm_system_wakeup(void); extern void pm_system_cancel_wakeup(void); -extern void pm_wakeup_clear(bool reset); +extern void pm_wakeup_clear(unsigned int irq_number); extern void pm_system_irq_wakeup(unsigned int irq_number); +extern unsigned int pm_wakeup_irq(void); extern bool pm_get_wakeup_count(unsigned int *count, bool block); extern bool pm_save_wakeup_count(unsigned int count); extern void pm_wakep_autosleep_enabled(bool set); diff --git a/kernel/power/main.c b/kernel/power/main.c index 44169f3081fd..7e646079fbeb 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -504,7 +504,10 @@ static ssize_t pm_wakeup_irq_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { - return pm_wakeup_irq ? sprintf(buf, "%u\n", pm_wakeup_irq) : -ENODATA; + if (!pm_wakeup_irq()) + return -ENODATA; + + return sprintf(buf, "%u\n", pm_wakeup_irq()); } power_attr_ro(pm_wakeup_irq); diff --git a/kernel/power/process.c b/kernel/power/process.c index b7e7798637b8..11b570fcf049 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -134,7 +134,7 @@ int freeze_processes(void) if (!pm_freezing) atomic_inc(&system_freezing_cnt); - pm_wakeup_clear(true); + pm_wakeup_clear(0); pr_info("Freezing user space processes ... "); pm_freezing = true; error = try_to_freeze_tasks(true); diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 80cc1f0f502b..6fcdee7e87a5 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -136,8 +136,6 @@ static void s2idle_loop(void) break; } - pm_wakeup_clear(false); - s2idle_enter(); } -- cgit v1.2.3