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authorBob Moore <robert.moore@intel.com>2008-04-10 19:06:38 +0400
committerLen Brown <len.brown@intel.com>2008-04-22 22:29:23 +0400
commite5567afa5cfa19e45f93c9c8796e46187a2d12f4 (patch)
treeab02e06e8a7aad960b1188b5211c1ed9d3631cf0 /drivers/acpi
parent235eebbdb501261e9960deb2a9a3459af44ec0ea (diff)
downloadlinux-e5567afa5cfa19e45f93c9c8796e46187a2d12f4.tar.xz
ACPICA: Fix for update of the Global Lock Handle
Fixed a problem where the global lock handle was not properly updated if a thread that acquired the global lock via executing AML code then attempted to acquire the lock via the AcpiAcquireGlobalLock interface. Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/events/evmisc.c13
-rw-r--r--drivers/acpi/events/evxface.c9
2 files changed, 14 insertions, 8 deletions
diff --git a/drivers/acpi/events/evmisc.c b/drivers/acpi/events/evmisc.c
index 2d34663dc1ed..d075062f5b89 100644
--- a/drivers/acpi/events/evmisc.c
+++ b/drivers/acpi/events/evmisc.c
@@ -461,6 +461,19 @@ acpi_status acpi_ev_acquire_global_lock(u16 timeout)
acpi_ev_global_lock_acquired++;
/*
+ * Update the global lock handle and check for wraparound. The handle is
+ * only used for the external global lock interfaces, but it is updated
+ * here to properly handle the case where a single thread may acquire the
+ * lock via both the AML and the acpi_acquire_global_lock interfaces. The
+ * handle is therefore updated on the first acquire from a given thread
+ * regardless of where the acquisition request originated.
+ */
+ acpi_gbl_global_lock_handle++;
+ if (acpi_gbl_global_lock_handle == 0) {
+ acpi_gbl_global_lock_handle = 1;
+ }
+
+ /*
* Make sure that a global lock actually exists. If not, just treat
* the lock as a standard mutex.
*/
diff --git a/drivers/acpi/events/evxface.c b/drivers/acpi/events/evxface.c
index e210aa2d76da..412cae698311 100644
--- a/drivers/acpi/events/evxface.c
+++ b/drivers/acpi/events/evxface.c
@@ -782,15 +782,8 @@ acpi_status acpi_acquire_global_lock(u16 timeout, u32 * handle)
acpi_os_get_thread_id());
if (ACPI_SUCCESS(status)) {
- /*
- * If this was the first acquisition of the Global Lock by this thread,
- * create a new handle. Otherwise, return the existing handle.
- */
- if (acpi_gbl_global_lock_mutex->mutex.acquisition_depth == 1) {
- acpi_gbl_global_lock_handle++;
- }
- /* Return the global lock handle */
+ /* Return the global lock handle (updated in acpi_ev_acquire_global_lock) */
*handle = acpi_gbl_global_lock_handle;
}