2011/3/24 Rafael J. Wysocki <rjw@xxxxxxx>:
> On Wednesday, March 23, 2011, Lin Ming wrote:
>> Commit 9cd0314(ACPI / ACPICA: Fix global lock acquisition) was backported
>> into ACPICA code base, and some divergence was introduced.
>>
>> This patch fixed it,
>> - rename acpi_ev_global_lock_pending/acpi_ev_global_lock_pending_lock
>> to acpi_gbl_global_lock_pending/acpi_gbl_global_lock_pending_lock.
>>
>> - move the initialization of acpi_gbl_global_lock_pending_lock from
>> acpi_ut_mutex_initialize to acpi_ev_init_global_lock_handler.
>>
>> Signed-off-by: Lin Ming <ming.m.lin@xxxxxxxxx>
>
> Reviewed-by: Rafael J. Wysocki <rjw@xxxxxxx>
Len,
Could you consider applying these patches for 2.6.39-rc1?
Thanks,
Lin Ming
>
>> ---
>> drivers/acpi/acpica/acglobal.h | 6 ++-
>> drivers/acpi/acpica/evmisc.c | 74 +++++++++++++++++++++------------------
>> drivers/acpi/acpica/utmutex.c | 5 ---
>> 3 files changed, 44 insertions(+), 41 deletions(-)
>>
>> diff --git a/drivers/acpi/acpica/acglobal.h b/drivers/acpi/acpica/acglobal.h
>> index 6d512fc..73863d8 100644
>> --- a/drivers/acpi/acpica/acglobal.h
>> +++ b/drivers/acpi/acpica/acglobal.h
>> @@ -214,13 +214,16 @@ ACPI_EXTERN struct acpi_mutex_info acpi_gbl_mutex_info[ACPI_NUM_MUTEX];
>>
>> /*
>> * Global lock mutex is an actual AML mutex object
>> - * Global lock semaphore works in conjunction with the HW global lock
>> + * Global lock semaphore works in conjunction with the actual global lock
>> + * Global lock spinlock is used for "pending" handshake
>> */
>> ACPI_EXTERN union acpi_operand_object *acpi_gbl_global_lock_mutex;
>> ACPI_EXTERN acpi_semaphore acpi_gbl_global_lock_semaphore;
>> +ACPI_EXTERN acpi_spinlock acpi_gbl_global_lock_pending_lock;
>> ACPI_EXTERN u16 acpi_gbl_global_lock_handle;
>> ACPI_EXTERN u8 acpi_gbl_global_lock_acquired;
>> ACPI_EXTERN u8 acpi_gbl_global_lock_present;
>> +ACPI_EXTERN u8 acpi_gbl_global_lock_pending;
>>
>> /*
>> * Spinlocks are used for interfaces that can be possibly called at
>> @@ -228,7 +231,6 @@ ACPI_EXTERN u8 acpi_gbl_global_lock_present;
>> */
>> 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_spinlock acpi_ev_global_lock_pending_lock; /* For global lock */
>>
>> /*****************************************************************************
>> *
>> diff --git a/drivers/acpi/acpica/evmisc.c b/drivers/acpi/acpica/evmisc.c
>> index 7dc8094..69a3b4a 100644
>> --- a/drivers/acpi/acpica/evmisc.c
>> +++ b/drivers/acpi/acpica/evmisc.c
>> @@ -284,39 +284,41 @@ static void ACPI_SYSTEM_XFACE acpi_ev_notify_dispatch(void *context)
>> * RETURN: ACPI_INTERRUPT_HANDLED
>> *
>> * DESCRIPTION: Invoked directly from the SCI handler when a global lock
>> - * release interrupt occurs. If there's a thread waiting for
>> - * the global lock, signal it.
>> - *
>> - * NOTE: Assumes that the semaphore can be signaled from interrupt level. If
>> - * this is not possible for some reason, a separate thread will have to be
>> - * scheduled to do this.
>> + * release interrupt occurs. If there is actually a pending
>> + * request for the lock, signal the waiting thread.
>> *
>> ******************************************************************************/
>> -static u8 acpi_ev_global_lock_pending;
>>
>> static u32 acpi_ev_global_lock_handler(void *context)
>> {
>> acpi_status status;
>> acpi_cpu_flags flags;
>>
>> - flags = acpi_os_acquire_lock(acpi_ev_global_lock_pending_lock);
>> + flags = acpi_os_acquire_lock(acpi_gbl_global_lock_pending_lock);
>>
>> - if (!acpi_ev_global_lock_pending) {
>> - goto out;
>> + /*
>> + * If a request for the global lock is not actually pending,
>> + * we are done. This handles "spurious" global lock interrupts
>> + * which are possible (and have been seen) with bad BIOSs.
>> + */
>> + if (!acpi_gbl_global_lock_pending) {
>> + goto cleanup_and_exit;
>> }
>>
>> - /* Send a unit to the semaphore */
>> -
>> + /*
>> + * Send a unit to the global lock semaphore. The actual acquisition
>> + * of the global lock will be performed by the waiting thread.
>> + */
>> status = acpi_os_signal_semaphore(acpi_gbl_global_lock_semaphore, 1);
>> if (ACPI_FAILURE(status)) {
>> ACPI_ERROR((AE_INFO, "Could not signal Global Lock semaphore"));
>> }
>>
>> - acpi_ev_global_lock_pending = FALSE;
>> + acpi_gbl_global_lock_pending = FALSE;
>>
>> - out:
>> - acpi_os_release_lock(acpi_ev_global_lock_pending_lock, flags);
>> +cleanup_and_exit:
>>
>> + acpi_os_release_lock(acpi_gbl_global_lock_pending_lock, flags);
>> return (ACPI_INTERRUPT_HANDLED);
>> }
>>
>> @@ -350,14 +352,20 @@ acpi_status acpi_ev_init_global_lock_handler(void)
>> * Map to AE_OK, but mark global lock as not present. Any attempt to
>> * actually use the global lock will be flagged with an error.
>> */
>> + acpi_gbl_global_lock_present = FALSE;
>> if (status == AE_NO_HARDWARE_RESPONSE) {
>> ACPI_ERROR((AE_INFO,
>> "No response from Global Lock hardware, disabling lock"));
>>
>> - acpi_gbl_global_lock_present = FALSE;
>> return_ACPI_STATUS(AE_OK);
>> }
>>
>> + status = acpi_os_create_lock(&acpi_gbl_global_lock_pending_lock);
>> + if (ACPI_FAILURE(status)) {
>> + return_ACPI_STATUS(status);
>> + }
>> +
>> + acpi_gbl_global_lock_pending = FALSE;
>> acpi_gbl_global_lock_present = TRUE;
>> return_ACPI_STATUS(status);
>> }
>> @@ -414,7 +422,7 @@ static int acpi_ev_global_lock_acquired;
>> acpi_status acpi_ev_acquire_global_lock(u16 timeout)
>> {
>> acpi_cpu_flags flags;
>> - acpi_status status = AE_OK;
>> + acpi_status status;
>> u8 acquired = FALSE;
>>
>> ACPI_FUNCTION_TRACE(ev_acquire_global_lock);
>> @@ -458,15 +466,15 @@ acpi_status acpi_ev_acquire_global_lock(u16 timeout)
>> }
>>
>> /*
>> - * Make sure that a global lock actually exists. If not, just treat the
>> - * lock as a standard mutex.
>> + * Make sure that a global lock actually exists. If not, just
>> + * treat the lock as a standard mutex.
>> */
>> if (!acpi_gbl_global_lock_present) {
>> acpi_gbl_global_lock_acquired = TRUE;
>> return_ACPI_STATUS(AE_OK);
>> }
>>
>> - flags = acpi_os_acquire_lock(acpi_ev_global_lock_pending_lock);
>> + flags = acpi_os_acquire_lock(acpi_gbl_global_lock_pending_lock);
>>
>> do {
>>
>> @@ -475,20 +483,19 @@ acpi_status acpi_ev_acquire_global_lock(u16 timeout)
>> ACPI_ACQUIRE_GLOBAL_LOCK(acpi_gbl_FACS, acquired);
>> if (acquired) {
>> acpi_gbl_global_lock_acquired = TRUE;
>> -
>> ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
>> "Acquired hardware Global Lock\n"));
>> break;
>> }
>>
>> - acpi_ev_global_lock_pending = TRUE;
>> -
>> - acpi_os_release_lock(acpi_ev_global_lock_pending_lock, flags);
>> -
>> /*
>> - * Did not get the lock. The pending bit was set above, and we
>> - * must wait until we get the global lock released interrupt.
>> + * Did not get the lock. The pending bit was set above, and
>> + * we must now wait until we receive the global lock
>> + * released interrupt.
>> */
>> + acpi_gbl_global_lock_pending = TRUE;
>> + acpi_os_release_lock(acpi_gbl_global_lock_pending_lock, flags);
>> +
>> ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
>> "Waiting for hardware Global Lock\n"));
>>
>> @@ -496,17 +503,16 @@ acpi_status acpi_ev_acquire_global_lock(u16 timeout)
>> * Wait for handshake with the global lock interrupt handler.
>> * This interface releases the interpreter if we must wait.
>> */
>> - status = acpi_ex_system_wait_semaphore(
>> - acpi_gbl_global_lock_semaphore,
>> - ACPI_WAIT_FOREVER);
>> + status =
>> + acpi_ex_system_wait_semaphore
>> + (acpi_gbl_global_lock_semaphore, ACPI_WAIT_FOREVER);
>>
>> - flags = acpi_os_acquire_lock(acpi_ev_global_lock_pending_lock);
>> + flags = acpi_os_acquire_lock(acpi_gbl_global_lock_pending_lock);
>>
>> } while (ACPI_SUCCESS(status));
>>
>> - acpi_ev_global_lock_pending = FALSE;
>> -
>> - acpi_os_release_lock(acpi_ev_global_lock_pending_lock, flags);
>> + acpi_gbl_global_lock_pending = FALSE;
>> + acpi_os_release_lock(acpi_gbl_global_lock_pending_lock, flags);
>>
>> return_ACPI_STATUS(status);
>> }
>> diff --git a/drivers/acpi/acpica/utmutex.c b/drivers/acpi/acpica/utmutex.c
>> index 519d4ee..7d797e2 100644
>> --- a/drivers/acpi/acpica/utmutex.c
>> +++ b/drivers/acpi/acpica/utmutex.c
>> @@ -93,11 +93,6 @@ acpi_status acpi_ut_mutex_initialize(void)
>> return_ACPI_STATUS (status);
>> }
>>
>> - status = acpi_os_create_lock (&acpi_ev_global_lock_pending_lock);
>> - if (ACPI_FAILURE (status)) {
>> - return_ACPI_STATUS (status);
>> - }
>> -
>> /* Mutex for _OSI support */
>> status = acpi_os_create_mutex(&acpi_gbl_osi_mutex);
>> if (ACPI_FAILURE(status)) {
>>
>
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