x86: acpi: Don't touch hardware on HW reduced platforms
If ACPI HW reduced bit in FADT is set we should ignore any ACPI hardware
communications.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/lib/acpi_table.c b/arch/x86/lib/acpi_table.c
index da6014f..3eb1011 100644
--- a/arch/x86/lib/acpi_table.c
+++ b/arch/x86/lib/acpi_table.c
@@ -463,6 +463,10 @@
debug("ACPI: done\n");
+ /* Don't touch ACPI hardware on HW reduced platforms */
+ if (fadt->flags & ACPI_FADT_HW_REDUCED_ACPI)
+ return current;
+
/*
* Other than waiting for OSPM to request us to switch to ACPI mode,
* do it by ourselves, since SMI will not be triggered.