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authorAlexey Starikovskiy <alexey.y.starikovskiy@linux.intel.com>2007-03-07 06:57:30 +0100
committerLen Brown <len.brown@intel.com>2007-03-07 06:57:30 +0100
commit610a3d069665ba2b27e42c90129ce640c4d6e515 (patch)
treecd6b4bf8526fe8a7bae944a8e9b0fad335c60b08
parentLinux 2.6.21-rc3 (diff)
downloadlinux-610a3d069665ba2b27e42c90129ce640c4d6e515.tar.xz
linux-610a3d069665ba2b27e42c90129ce640c4d6e515.zip
ACPICA: Fix ACPI Global Lock re-entrancy
patch "Delete recursive feature of ACPI Global Lock" broke re-entrancy of the Global Lock. The common routine to acquire GL is acpi_ev_acquire_global_lock, so check for re-entrancy _must_ be there, and not anywhere else. http://bugzilla.kernel.org/show_bug.cgi?id=8066#c9 Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@linux.intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
-rw-r--r--drivers/acpi/events/evmisc.c25
1 files changed, 23 insertions, 2 deletions
diff --git a/drivers/acpi/events/evmisc.c b/drivers/acpi/events/evmisc.c
index d572700197f3..8dcade63b04b 100644
--- a/drivers/acpi/events/evmisc.c
+++ b/drivers/acpi/events/evmisc.c
@@ -423,6 +423,8 @@ static acpi_status acpi_ev_remove_global_lock_handler(void)
* the global lock appear as a standard mutex on the OS side.
*
*****************************************************************************/
+static acpi_thread_id acpi_ev_global_lock_thread_id;
+static int acpi_ev_global_lock_acquired;
acpi_status acpi_ev_acquire_global_lock(u16 timeout)
{
@@ -435,11 +437,24 @@ acpi_status acpi_ev_acquire_global_lock(u16 timeout)
* Only one thread can acquire the GL at a time, the global_lock_mutex
* enforces this. This interface releases the interpreter if we must wait.
*/
- status = acpi_ex_system_wait_mutex(acpi_gbl_global_lock_mutex, timeout);
+ status = acpi_ex_system_wait_mutex(acpi_gbl_global_lock_mutex, 0);
+ if (status == AE_TIME) {
+ if (acpi_ev_global_lock_thread_id == acpi_os_get_thread_id()) {
+ acpi_ev_global_lock_acquired++;
+ return AE_OK;
+ }
+ }
+
+ if (ACPI_FAILURE(status)) {
+ status = acpi_ex_system_wait_mutex(acpi_gbl_global_lock_mutex, timeout);
+ }
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
+ acpi_ev_global_lock_thread_id = acpi_os_get_thread_id();
+ acpi_ev_global_lock_acquired++;
+
/*
* Make sure that a global lock actually exists. If not, just treat
* the lock as a standard mutex.
@@ -506,6 +521,11 @@ acpi_status acpi_ev_release_global_lock(void)
return_ACPI_STATUS(AE_NOT_ACQUIRED);
}
+ acpi_ev_global_lock_acquired--;
+ if (acpi_ev_global_lock_acquired > 0) {
+ return AE_OK;
+ }
+
if (acpi_gbl_global_lock_present) {
/* Allow any thread to release the lock */
@@ -529,7 +549,8 @@ acpi_status acpi_ev_release_global_lock(void)
acpi_gbl_global_lock_acquired = FALSE;
/* Release the local GL mutex */
-
+ acpi_ev_global_lock_thread_id = 0;
+ acpi_ev_global_lock_acquired = 0;
acpi_os_release_mutex(acpi_gbl_global_lock_mutex);
return_ACPI_STATUS(status);
}