From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> The addition of might_sleep() to down_timeout() caused the latter to enable interrupts unconditionally in some cases, which in turn broke the ACPI S3 wakeup path in acpi_suspend_enter(), where down_timeout() is called by acpi_disable_all_gpes() via acpi_ut_acquire_mutex(). Namely, if CONFIG_DEBUG_ATOMIC_SLEEP is set, might_sleep() causes might_resched() to be used and if CONFIG_PREEMPT_VOLUNTARY is set, this triggers __cond_resched() which may call preempt_schedule_common(), so __schedule() gets invoked and it ends up with enabled interrupts (in the prev == next case). Now, enabling interrupts early in the S3 wakeup path causes the kernel to crash. Address this by modifying acpi_suspend_enter() to disable GPEs without attempting to acquire the sleeping lock which is not needed in that code path anyway. Fixes: 99409b935c9a locking/semaphore: Add might_sleep() to down_*() family Reported-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> --- drivers/acpi/acpica/achware.h | 2 -- drivers/acpi/sleep.c | 16 ++++++++++++---- include/acpi/acpixf.h | 1 + 3 files changed, 13 insertions(+), 6 deletions(-) Index: linux-pm/drivers/acpi/acpica/achware.h =================================================================== --- linux-pm.orig/drivers/acpi/acpica/achware.h +++ linux-pm/drivers/acpi/acpica/achware.h @@ -101,8 +101,6 @@ acpi_status acpi_hw_get_gpe_status(struct acpi_gpe_event_info *gpe_event_info, acpi_event_status *event_status); -acpi_status acpi_hw_disable_all_gpes(void); - acpi_status acpi_hw_enable_all_runtime_gpes(void); acpi_status acpi_hw_enable_all_wakeup_gpes(void); Index: linux-pm/include/acpi/acpixf.h =================================================================== --- linux-pm.orig/include/acpi/acpixf.h +++ linux-pm/include/acpi/acpixf.h @@ -761,6 +761,7 @@ ACPI_HW_DEPENDENT_RETURN_STATUS(acpi_sta acpi_event_status *event_status)) ACPI_HW_DEPENDENT_RETURN_UINT32(u32 acpi_dispatch_gpe(acpi_handle gpe_device, u32 gpe_number)) +ACPI_HW_DEPENDENT_RETURN_STATUS(acpi_status acpi_hw_disable_all_gpes(void)) ACPI_HW_DEPENDENT_RETURN_STATUS(acpi_status acpi_disable_all_gpes(void)) ACPI_HW_DEPENDENT_RETURN_STATUS(acpi_status acpi_enable_all_runtime_gpes(void)) ACPI_HW_DEPENDENT_RETURN_STATUS(acpi_status acpi_enable_all_wakeup_gpes(void)) Index: linux-pm/drivers/acpi/sleep.c =================================================================== --- linux-pm.orig/drivers/acpi/sleep.c +++ linux-pm/drivers/acpi/sleep.c @@ -636,11 +636,19 @@ static int acpi_suspend_enter(suspend_st } /* - * Disable and clear GPE status before interrupt is enabled. Some GPEs - * (like wakeup GPE) haven't handler, this can avoid such GPE misfire. - * acpi_leave_sleep_state will reenable specific GPEs later + * Disable all GPE and clear their status bits before interrupts are + * enabled. Some GPEs (like wakeup GPEs) have no handlers and this can + * prevent them from producing spurious interrups. + * + * acpi_leave_sleep_state() will reenable specific GPEs later. + * + * Because this code runs on one CPU with disabled interrupts (all of + * the other CPUs are offline at that time), it need not acquire any + * sleeping locks which maybe harmful due to instrumentation even if + * those locks are not contended, so avoid doing that by using a low- + * level library routine here. */ - acpi_disable_all_gpes(); + acpi_hw_disable_all_gpes(); /* Allow EC transactions to happen. */ acpi_ec_unblock_transactions();
