--- zzzz-none-000/linux-3.10.107/drivers/acpi/acpica/hwtimer.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/acpi/acpica/hwtimer.c	2021-02-04 17:41:59.000000000 +0000
@@ -5,7 +5,7 @@
  *****************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2013, Intel Corp.
+ * Copyright (C) 2000 - 2015, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -41,7 +41,8 @@
  * POSSIBILITY OF SUCH DAMAGES.
  */
 
-#include <linux/export.h>
+#define EXPORT_ACPI_INTERFACES
+
 #include <acpi/acpi.h>
 #include "accommon.h"
 
@@ -100,8 +101,13 @@
 		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 +154,12 @@
 		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.