Commit 610a3d06 authored by Alexey Starikovskiy's avatar Alexey Starikovskiy Committed by Len Brown
Browse files

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: default avatarAlexey Starikovskiy <alexey.y.starikovskiy@linux.intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 08e15e81

drivers/acpi/events/evmisc.c

+23 −2
Original line number Diff line number Diff line
@@ -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, 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);

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE