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authorLv Zheng <lv.zheng@intel.com>2013-06-08 00:59:18 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-07-21 18:21:28 -0700
commit22a5fdfc36cd18abfd421699e9076307fa54dae4 (patch)
treea8138e47450764352098f326c5cfc76980b69649
parent93ede471186348e7a82b13a879213fd661c951be (diff)
downloadvexpress-lsk-22a5fdfc36cd18abfd421699e9076307fa54dae4.tar.gz
ACPICA: Do not use extended sleep registers unless HW-reduced bit is set
commit 7cec7048fe22e3e92389da2cd67098f6c4284e7f upstream. 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. Reported-by: Daniel Rowe <bart@fathom13.com> References: https://bugzilla.kernel.org/show_bug.cgi?id=54181 References: https://bugs.acpica.org/show_bug.cgi?id=1020 Bisected-by: Brint E. Kriebel <kernel@bekit.net> 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/acpi/acpica/hwxfsleep.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/acpi/acpica/hwxfsleep.c b/drivers/acpi/acpica/hwxfsleep.c
index 35eebdac0f9..09b06e2feff 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 */