From 382fabb2974a153de73949e4bbd033c3235dac76 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Fri, 21 Jul 2017 22:32:06 +0300 Subject: [PATCH] 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 Reviewed-by: Bin Meng --- arch/x86/lib/acpi_table.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/lib/acpi_table.c b/arch/x86/lib/acpi_table.c index da6014fb41..3eb101105b 100644 --- a/arch/x86/lib/acpi_table.c +++ b/arch/x86/lib/acpi_table.c @@ -463,6 +463,10 @@ ulong write_acpi_tables(ulong start) 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. -- 2.39.5