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authorLin Ming <ming.m.lin@intel.com>2011-03-23 10:26:36 +0100
committerLen Brown <len.brown@intel.com>2011-03-25 09:33:15 +0100
commit749c27639b95c5c4a8185e02a4efb189034944ed (patch)
treebb20d0d20fbc325f676949a4a240beefb9d53f9a /drivers/acpi/acpica/evmisc.c
parentACPICA: Use acpi_os_create_lock interface (diff)
downloadlinux-749c27639b95c5c4a8185e02a4efb189034944ed.tar.xz
linux-749c27639b95c5c4a8185e02a4efb189034944ed.zip
ACPICA: Fix code divergence of global lock handling
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@intel.com> Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/acpica/evmisc.c')
-rw-r--r--drivers/acpi/acpica/evmisc.c74
1 files changed, 40 insertions, 34 deletions
diff --git a/drivers/acpi/acpica/evmisc.c b/drivers/acpi/acpica/evmisc.c
index 7dc80946f7bd..69a3b4aa862b 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);
}