From 7cec7048fe22e3e92389da2cd67098f6c4284e7f Mon Sep 17 00:00:00 2001 From: Lv Zheng Date: Sat, 8 Jun 2013 00:59:18 +0000 Subject: [PATCH] ACPICA: Do not use extended sleep registers unless HW-reduced bit is set Previous implementation incorrectly used the ACPI 5.0 extended sleep registers if they were simply populated. This caused problems on some non-HW-reduced machines. As per the ACPI spec, they should only be used if the HW-reduced bit is set. Lv Zheng, ACPICA BZ 1020. References: https://bugzilla.kernel.org/show_bug.cgi?id=54181 References: https://bugs.acpica.org/show_bug.cgi?id=1020 Reported-by: Daniel Rowe Bisected-by: Brint E. Kriebel Cc: 3.4+ Signed-off-by: Lv Zheng Signed-off-by: Bob Moore Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpica/hwxfsleep.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/acpica/hwxfsleep.c b/drivers/acpi/acpica/hwxfsleep.c index 111849c2117f..f2e669db8b65 100644 --- a/drivers/acpi/acpica/hwxfsleep.c +++ b/drivers/acpi/acpica/hwxfsleep.c @@ -240,12 +240,14 @@ static acpi_status acpi_hw_sleep_dispatch(u8 sleep_state, u32 function_id) &acpi_sleep_dispatch[function_id]; #if (!ACPI_REDUCED_HARDWARE) - /* * If the Hardware Reduced flag is set (from the FADT), we must - * use the extended sleep registers + * use the extended sleep registers (FADT). Note: As per the ACPI + * specification, these extended registers are to be used for HW-reduced + * platforms only. They are not general-purpose replacements for the + * legacy PM register sleep support. */ - if (acpi_gbl_reduced_hardware || acpi_gbl_FADT.sleep_control.address) { + if (acpi_gbl_reduced_hardware) { status = sleep_functions->extended_function(sleep_state); } else { /* Legacy sleep */ -- 2.39.5