[77/88] ACPICA: Do not use extended sleep registers unless HW-reduced bit is set

Steven Rostedt
2013-08-13T16:34:50Z

[-- Attachment #1: 0077-ACPICA-Do-not-use-extended-sleep-registers-unless-HW.patch --]
[-- Type: text/plain, Size: 1956 bytes --]

3.6.11.7-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Lv Zheng <lv.zheng@intel.com>

[ Upstream commit 7cec7048fe22e3e92389da2cd67098f6c4284e7f ]

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 <bart@fathom13.com>
Bisected-by: Brint E. Kriebel <kernel@bekit.net>
Cc: 3.4+ <stable@vger.kernel.org>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
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 1f165a7..c92753b 100644
--- a/drivers/acpi/acpica/hwxfsleep.c
+++ b/drivers/acpi/acpica/hwxfsleep.c
@@ -242,12 +242,14 @@ 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 */
--
1.7.10.4