ACPICA: Convert acpi_gbl_hardware lock back to an acpi_raw_spinlock

We hit the following bug with -RT:

|BUG: scheduling while atomic: swapper/7/0/0x00000002
|Pid: 0, comm: swapper/7 Not tainted 3.6.11-rt28.19.el6rt.x86_64.debug #1
|Call Trace:
|  rt_spin_lock+0x16/0x40
|  __schedule_bug+0x67/0x90
|  __schedule+0x793/0x7a0
|  acpi_os_acquire_lock+0x1f/0x23
|  acpi_write_bit_register+0x33/0xb0
|  rt_spin_lock_slowlock+0xe5/0x2f0
|  acpi_idle_enter_bm+0x8a/0x28e
…
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 <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1360765565.23152.5.camel@gandalf.local.home
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bigeasy: shorten the backtrace, use the type acpi_raw_spinlock incl.
 accessor]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/acpica/acglobal.h b/drivers/acpi/acpica/acglobal.h
index 0bc550072a21426815ba17dcb5ea9622b9a392b8..1e6204518496cffb6f02953d1ee1b3a12561f22a 100644 (file)
--- a/drivers/acpi/acpica/acglobal.h
+++ b/drivers/acpi/acpica/acglobal.h
@@ -82,7 +82,7 @@ ACPI_GLOBAL(u8, acpi_gbl_global_lock_pending);
  * interrupt level
  */
 ACPI_GLOBAL(acpi_spinlock, acpi_gbl_gpe_lock); /* For GPE data structs and registers */
-ACPI_GLOBAL(acpi_spinlock, acpi_gbl_hardware_lock);    /* For ACPI H/W except GPE registers */
+ACPI_GLOBAL(acpi_raw_spinlock, acpi_gbl_hardware_lock);        /* For ACPI H/W except GPE registers */
 ACPI_GLOBAL(acpi_spinlock, acpi_gbl_reference_count_lock);
 
 /* Mutex for _OSI support */

diff --git a/drivers/acpi/acpica/hwregs.c b/drivers/acpi/acpica/hwregs.c
index 27a86ad55b58617cc6393910f54dbc3f75a6ff6e..3de794bcf8fa8c1bf906ca5ac6f4d422ec5e0faa 100644 (file)
--- a/drivers/acpi/acpica/hwregs.c
+++ b/drivers/acpi/acpica/hwregs.c
@@ -390,14 +390,14 @@ acpi_status acpi_hw_clear_acpi_status(void)
                          ACPI_BITMASK_ALL_FIXED_STATUS,
                          ACPI_FORMAT_UINT64(acpi_gbl_xpm1a_status.address)));
 
-       lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
+       lock_flags = acpi_os_acquire_raw_lock(acpi_gbl_hardware_lock);
 
        /* 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);
+       acpi_os_release_raw_lock(acpi_gbl_hardware_lock, lock_flags);
 
        if (ACPI_FAILURE(status)) {
                goto exit;

diff --git a/drivers/acpi/acpica/hwxface.c b/drivers/acpi/acpica/hwxface.c
index 5d1396870bd0b421d42b21bb8b425f62b6d20250..6e39a771a56efb7021bd9f07654b3ca5dbdd8d9c 100644 (file)
--- a/drivers/acpi/acpica/hwxface.c
+++ b/drivers/acpi/acpica/hwxface.c
@@ -227,7 +227,7 @@ acpi_status acpi_write_bit_register(u32 register_id, u32 value)
                return_ACPI_STATUS(AE_BAD_PARAMETER);
        }
 
-       lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
+       lock_flags = acpi_os_acquire_raw_lock(acpi_gbl_hardware_lock);
 
        /*
         * At this point, we know that the parent register is one of the
@@ -288,7 +288,7 @@ acpi_status acpi_write_bit_register(u32 register_id, u32 value)
 
 unlock_and_exit:
 
-       acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
+       acpi_os_release_raw_lock(acpi_gbl_hardware_lock, lock_flags);
        return_ACPI_STATUS(status);
 }
 

diff --git a/drivers/acpi/acpica/utmutex.c b/drivers/acpi/acpica/utmutex.c
index d2d93e388f40873bb573d7737b2551f6c7d8e31a..2e465e6a0ab65a30f462a8aedff78a54d9e6df99 100644 (file)
--- a/drivers/acpi/acpica/utmutex.c
+++ b/drivers/acpi/acpica/utmutex.c
@@ -52,7 +52,7 @@ acpi_status acpi_ut_mutex_initialize(void)
                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);
        }
@@ -109,7 +109,7 @@ 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);
        acpi_os_delete_lock(acpi_gbl_reference_count_lock);
 
        /* Delete the reader/writer lock */