[PATCH 46/140] ACPICA: Release global lock from interrupt handler

Len Brown
2007-02-07T18:54:03Z

From: Bob Moore <robert.moore@intel.com>

The ACPI Global Lock interrupt handler no longer
queues the execution of a separate thread to signal the
global lock semaphore. Instead, the semaphore is signaled
directly from the interrupt handler.

Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
---
drivers/acpi/events/evmisc.c | 50 ++++++++++++-----------------------------
1 files changed, 15 insertions(+), 35 deletions(-)

diff --git a/drivers/acpi/events/evmisc.c b/drivers/acpi/events/evmisc.c
index f82b81c..00f33ed 100644
--- a/drivers/acpi/events/evmisc.c
+++ b/drivers/acpi/events/evmisc.c
@@ -67,8 +67,6 @@ static const char *acpi_notify_value_names[] = {

static void ACPI_SYSTEM_XFACE acpi_ev_notify_dispatch(void *context);

-static void ACPI_SYSTEM_XFACE acpi_ev_global_lock_thread(void *context);
-
static u32 acpi_ev_global_lock_handler(void *context);

/*******************************************************************************
@@ -282,43 +280,19 @@ static void ACPI_SYSTEM_XFACE acpi_ev_notify_dispatch(void *context)

/*******************************************************************************
*
- * FUNCTION: acpi_ev_global_lock_thread
- *
- * PARAMETERS: Context - From thread interface, not used
- *
- * RETURN: None
- *
- * DESCRIPTION: Invoked by SCI interrupt handler upon acquisition of the
- * Global Lock. Simply signal all threads that are waiting
- * for the lock.
- *
- ******************************************************************************/
-
-static void ACPI_SYSTEM_XFACE acpi_ev_global_lock_thread(void *context)
-{
- acpi_status status;
-
- /* Signal the thread that is waiting for the lock */
-
- /* Send a unit to the semaphore */
-
- 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"));
- }
-}
-
-/*******************************************************************************
- *
* FUNCTION: acpi_ev_global_lock_handler
*
* PARAMETERS: Context - From thread interface, not used
*
- * RETURN: ACPI_INTERRUPT_HANDLED or ACPI_INTERRUPT_NOT_HANDLED
+ * RETURN: ACPI_INTERRUPT_HANDLED
*
* DESCRIPTION: Invoked directly from the SCI handler when a global lock
- * release interrupt occurs. Grab the global lock and queue
- * the global lock thread for execution
+ * release interrupt occurs. Attempt to acquire the global lock,
+ * if successful, signal the thread waiting for the lock.
+ *
+ * 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.
*
******************************************************************************/

@@ -338,7 +312,13 @@ static u32 acpi_ev_global_lock_handler(void *context)
/* Got the lock, now wake all threads waiting for it */

acpi_gbl_global_lock_acquired = TRUE;
- acpi_ev_global_lock_thread(context);
+ /* Send a unit to the semaphore */
+
+ if (ACPI_FAILURE(acpi_os_signal_semaphore(
+ acpi_gbl_global_lock_semaphore, 1))) {
+ ACPI_ERROR((AE_INFO,
+ "Could not signal Global Lock semaphore"));
+ }
}

return (ACPI_INTERRUPT_HANDLED);
@@ -480,7 +460,7 @@ acpi_status acpi_ev_release_global_lock(void)

ACPI_FUNCTION_TRACE(ev_release_global_lock);

- /* Lock must be acquired */
+ /* Lock must be already acquired */

if (!acpi_gbl_global_lock_acquired) {
ACPI_WARNING((AE_INFO,
--
1.5.0.rc3.39.gec804