Merge tag 'v3.12'

Linux 3.12

Conflicts:
	fs/exec.c

1 files changed, 12 insertions, 1 deletions

diff --git a/drivers/acpi/acpica/hwtimer.c b/drivers/acpi/acpica/hwtimer.c
index 0c1a8bbd05d6..2d7d22ebc782 100644
--- a/drivers/acpi/acpica/hwtimer.c
+++ b/drivers/acpi/acpica/hwtimer.c
@@ -100,8 +100,13 @@ acpi_status acpi_get_timer(u32 * ticks)
 		return_ACPI_STATUS(AE_BAD_PARAMETER);
 	}
 
-	status = acpi_hw_read(ticks, &acpi_gbl_FADT.xpm_timer_block);
+	/* ACPI 5.0A: PM Timer is optional */
+
+	if (!acpi_gbl_FADT.xpm_timer_block.address) {
+		return_ACPI_STATUS(AE_SUPPORT);
+	}
 
+	status = acpi_hw_read(ticks, &acpi_gbl_FADT.xpm_timer_block);
 	return_ACPI_STATUS(status);
 }
 
@@ -148,6 +153,12 @@ acpi_get_timer_duration(u32 start_ticks, u32 end_ticks, u32 * time_elapsed)
 		return_ACPI_STATUS(AE_BAD_PARAMETER);
 	}
 
+	/* ACPI 5.0A: PM Timer is optional */
+
+	if (!acpi_gbl_FADT.xpm_timer_block.address) {
+		return_ACPI_STATUS(AE_SUPPORT);
+	}
+
 	/*
 	 * Compute Tick Delta:
 	 * Handle (max one) timer rollovers on 24-bit versus 32-bit timers.