diff --git a/[refs] b/[refs]
index d24fc651e3b8..7cb5b30450bc 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d70326689b70b35527765bd3decbb1229459e928
+refs/heads/master: 9cbfa18e8a7b34a32eddbd914a07f085962f50a8
diff --git a/trunk/drivers/acpi/acpica/acconfig.h b/trunk/drivers/acpi/acpica/acconfig.h
index 33181ad350d5..b17d8de9f6ff 100644
--- a/trunk/drivers/acpi/acpica/acconfig.h
+++ b/trunk/drivers/acpi/acpica/acconfig.h
@@ -119,6 +119,10 @@
 
 #define ACPI_MAX_LOOP_ITERATIONS        0xFFFF
 
+/* Maximum sleep allowed via Sleep() operator */
+
+#define ACPI_MAX_SLEEP                  20000	/* Two seconds */
+
 /******************************************************************************
  *
  * ACPI Specification constants (Do not change unless the specification changes)
diff --git a/trunk/drivers/acpi/acpica/exsystem.c b/trunk/drivers/acpi/acpica/exsystem.c
index 6d32e09327f1..675aaa91a770 100644
--- a/trunk/drivers/acpi/acpica/exsystem.c
+++ b/trunk/drivers/acpi/acpica/exsystem.c
@@ -201,6 +201,14 @@ acpi_status acpi_ex_system_do_sleep(u64 how_long)
 
 	acpi_ex_relinquish_interpreter();
 
+	/*
+	 * For compatibility with other ACPI implementations and to prevent
+	 * accidental deep sleeps, limit the sleep time to something reasonable.
+	 */
+	if (how_long > ACPI_MAX_SLEEP) {
+		how_long = ACPI_MAX_SLEEP;
+	}
+
 	acpi_os_sleep(how_long);
 
 	/* And now we must get the interpreter again */