Subject: acpi/rt: Convert acpi_gbl_hardware lock back to a raw_spinlock_t From: Steven Rostedt Date: Wed, 13 Feb 2013 09:26:05 -0500 We hit the following bug with 3.6-rt: [ 5.898990] BUG: scheduling while atomic: swapper/3/0/0x00000002 [ 5.898991] no locks held by swapper/3/0. [ 5.898993] Modules linked in: [ 5.898996] Pid: 0, comm: swapper/3 Not tainted 3.6.11-rt28.19.el6rt.x86_64.debug #1 [ 5.898997] Call Trace: [ 5.899011] [] __schedule_bug+0x67/0x90 [ 5.899028] [] __schedule+0x793/0x7a0 [ 5.899032] [] ? debug_rt_mutex_print_deadlock+0x50/0x200 [ 5.899034] [] schedule+0x29/0x70 [ 5.899036] BUG: scheduling while atomic: swapper/7/0/0x00000002 [ 5.899037] no locks held by swapper/7/0. [ 5.899039] [] rt_spin_lock_slowlock+0xe5/0x2f0 [ 5.899040] Modules linked in: [ 5.899041] [ 5.899045] [] ? _raw_spin_unlock_irqrestore+0x38/0x90 [ 5.899046] Pid: 0, comm: swapper/7 Not tainted 3.6.11-rt28.19.el6rt.x86_64.debug #1 [ 5.899047] Call Trace: [ 5.899049] [] rt_spin_lock+0x16/0x40 [ 5.899052] [] __schedule_bug+0x67/0x90 [ 5.899054] [] ? notifier_call_chain+0x80/0x80 [ 5.899056] [] __schedule+0x793/0x7a0 [ 5.899059] [] acpi_os_acquire_lock+0x1f/0x23 [ 5.899062] [] ? debug_rt_mutex_print_deadlock+0x50/0x200 [ 5.899068] [] acpi_write_bit_register+0x33/0xb0 [ 5.899071] [] schedule+0x29/0x70 [ 5.899072] [] ? acpi_read_bit_register+0x33/0x51 [ 5.899074] [] rt_spin_lock_slowlock+0xe5/0x2f0 [ 5.899077] [] acpi_idle_enter_bm+0x8a/0x28e [ 5.899079] [] ? _raw_spin_unlock_irqrestore+0x38/0x90 [ 5.899081] [] ? this_cpu_load+0x1a/0x30 [ 5.899083] [] rt_spin_lock+0x16/0x40 [ 5.899087] [] cpuidle_enter+0x19/0x20 [ 5.899088] [] ? notifier_call_chain+0x80/0x80 [ 5.899090] [] cpuidle_enter_state+0x17/0x50 [ 5.899092] [] acpi_os_acquire_lock+0x1f/0x23 [ 5.899094] [] cpuidle899101] [] ? As the acpi code disables interrupts in acpi_idle_enter_bm, and calls code that grabs the acpi lock, it causes issues as the lock is currently in RT a sleeping lock. The lock was converted from a raw to a sleeping lock due to some previous issues, and tests that showed it didn't seem to matter. Unfortunately, it did matter for one of our boxes. This patch converts the lock back to a raw lock. I've run this code on a few of my own machines, one being my laptop that uses the acpi quite extensively. I've been able to suspend and resume without issues. [ tglx: Made the change exclusive for acpi_gbl_hardware_lock ] Signed-off-by: Steven Rostedt Cc: John Kacur Cc: Clark Williams Link: http://lkml.kernel.org/r/1360765565.23152.5.camel@gandalf.local.home Cc: stable-rt@vger.kernel.org Signed-off-by: Thomas Gleixner --- drivers/acpi/acpica/acglobal.h | 2 +- drivers/acpi/acpica/hwregs.c | 4 ++-- drivers/acpi/acpica/hwxface.c | 4 ++-- drivers/acpi/acpica/utmutex.c | 4 ++-- include/acpi/platform/aclinux.h | 14 ++++++++++++++ 5 files changed, 21 insertions(+), 7 deletions(-) Index: linux-stable/drivers/acpi/acpica/acglobal.h =================================================================== --- linux-stable.orig/drivers/acpi/acpica/acglobal.h +++ linux-stable/drivers/acpi/acpica/acglobal.h @@ -251,7 +251,7 @@ ACPI_EXTERN u8 acpi_gbl_global_lock_pend * interrupt level */ ACPI_EXTERN acpi_spinlock acpi_gbl_gpe_lock; /* For GPE data structs and registers */ -ACPI_EXTERN acpi_spinlock acpi_gbl_hardware_lock; /* For ACPI H/W except GPE registers */ +ACPI_EXTERN acpi_raw_spinlock acpi_gbl_hardware_lock; /* For ACPI H/W except GPE registers */ /***************************************************************************** * Index: linux-stable/drivers/acpi/acpica/hwregs.c =================================================================== --- linux-stable.orig/drivers/acpi/acpica/hwregs.c +++ linux-stable/drivers/acpi/acpica/hwregs.c @@ -271,14 +271,14 @@ acpi_status acpi_hw_clear_acpi_status(vo ACPI_BITMASK_ALL_FIXED_STATUS, ACPI_FORMAT_UINT64(acpi_gbl_xpm1a_status.address))); - lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock); + raw_spin_lock_irqsave(acpi_gbl_hardware_lock, lock_flags); /* Clear the fixed events in PM1 A/B */ status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS, ACPI_BITMASK_ALL_FIXED_STATUS); - acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags); + raw_spin_unlock_irqrestore(acpi_gbl_hardware_lock, lock_flags); if (ACPI_FAILURE(status)) goto exit; Index: linux-stable/drivers/acpi/acpica/hwxface.c =================================================================== --- linux-stable.orig/drivers/acpi/acpica/hwxface.c +++ linux-stable/drivers/acpi/acpica/hwxface.c @@ -366,7 +366,7 @@ acpi_status acpi_write_bit_register(u32 return_ACPI_STATUS(AE_BAD_PARAMETER); } - lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock); + raw_spin_lock_irqsave(acpi_gbl_hardware_lock, lock_flags); /* * At this point, we know that the parent register is one of the @@ -427,7 +427,7 @@ acpi_status acpi_write_bit_register(u32 unlock_and_exit: - acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags); + raw_spin_unlock_irqrestore(acpi_gbl_hardware_lock, lock_flags); return_ACPI_STATUS(status); } Index: linux-stable/drivers/acpi/acpica/utmutex.c =================================================================== --- linux-stable.orig/drivers/acpi/acpica/utmutex.c +++ linux-stable/drivers/acpi/acpica/utmutex.c @@ -88,7 +88,7 @@ acpi_status acpi_ut_mutex_initialize(voi return_ACPI_STATUS (status); } - status = acpi_os_create_lock (&acpi_gbl_hardware_lock); + status = acpi_os_create_raw_lock (&acpi_gbl_hardware_lock); if (ACPI_FAILURE (status)) { return_ACPI_STATUS (status); } @@ -135,7 +135,7 @@ void acpi_ut_mutex_terminate(void) /* Delete the spinlocks */ acpi_os_delete_lock(acpi_gbl_gpe_lock); - acpi_os_delete_lock(acpi_gbl_hardware_lock); + acpi_os_delete_raw_lock(acpi_gbl_hardware_lock); /* Delete the reader/writer lock */ Index: linux-stable/include/acpi/platform/aclinux.h =================================================================== --- linux-stable.orig/include/acpi/platform/aclinux.h +++ linux-stable/include/acpi/platform/aclinux.h @@ -72,6 +72,7 @@ #define acpi_cache_t struct kmem_cache #define acpi_spinlock spinlock_t * +#define acpi_raw_spinlock raw_spinlock_t * #define acpi_cpu_flags unsigned long #else /* !__KERNEL__ */ @@ -175,6 +176,19 @@ static inline void *acpi_os_acquire_obje lock ? AE_OK : AE_NO_MEMORY; \ }) +#define acpi_os_create_raw_lock(__handle) \ +({ \ + raw_spinlock_t *lock = ACPI_ALLOCATE(sizeof(*lock)); \ + \ + if (lock) { \ + *(__handle) = lock; \ + raw_spin_lock_init(*(__handle)); \ + } \ + lock ? AE_OK : AE_NO_MEMORY; \ +}) + +#define acpi_os_delete_raw_lock(__handle) kfree(__handle) + #endif /* __KERNEL__ */ #endif /* __ACLINUX_H__ */