Merge tag 'pm-for-3.5-rc7' of git://git.kernel.org/pub/scm/linux/kern…

…el/git/rafael/linux-pm

Pull power management fix from Rafael Wysocki:
 "This removes ACPICA code that had already been removed once from the
  kernel already by commit 2780cc4660e1 ("[ACPI] Fix suspend/resume
  lockup issue by leaving Bus Master Arbitration enabled"), because it
  was known to cause systems to lock up during resume from suspend, but
  was re-introduced by mistake during the v3.4 merge window."

* tag 'pm-for-3.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / PM: Leave Bus Master Arbitration enabled for suspend/resume

drivers/acpi/acpica/hwsleep.c

@@ -95,18 +95,6 @@ acpi_status acpi_hw_legacy_sleep(u8 sleep_state, u8 flags)
 		return_ACPI_STATUS(status);
 	}
 
-	if (sleep_state != ACPI_STATE_S5) {
-		/*
-		 * Disable BM arbitration. This feature is contained within an
-		 * optional register (PM2 Control), so ignore a BAD_ADDRESS
-		 * exception.
-		 */
-		status = acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
-		if (ACPI_FAILURE(status) && (status != AE_BAD_ADDRESS)) {
-			return_ACPI_STATUS(status);
-		}
-	}
-
 	/*
 	 * 1) Disable/Clear all GPEs
 	 * 2) Enable all wakeup GPEs
@@ -364,16 +352,6 @@ acpi_status acpi_hw_legacy_wake(u8 sleep_state, u8 flags)
 				    [ACPI_EVENT_POWER_BUTTON].
 				    status_register_id, ACPI_CLEAR_STATUS);
 
-	/*
-	 * Enable BM arbitration. This feature is contained within an
-	 * optional register (PM2 Control), so ignore a BAD_ADDRESS
-	 * exception.
-	 */
-	status = acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
-	if (ACPI_FAILURE(status) && (status != AE_BAD_ADDRESS)) {
-		return_ACPI_STATUS(status);
-	}
-
 	acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WORKING);
 	return_ACPI_STATUS(status);
 }