[PATCH 3.12 67/77] ACPI / Battery: Add a _BIX quirk for NEC LZ750/LS

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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

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

From: Lan Tianyu <tianyu.lan@intel.com>

commit a90b40385735af0d3031f98e97b439e8944a31b3 upstream.

The AML method _BIX of NEC LZ750/LS returns a broken package which
skips the first member "Revision" (ACPI 5.0, Table 10-234).

Add a quirk for this machine to skip member "Revision" during parsing
the package returned by _BIX.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=67351
Reported-and-tested-by: Francisco Castro <fcr@adinet.com.uy>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/acpi/battery.c |   21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -68,6 +68,7 @@ MODULE_AUTHOR("Alexey Starikovskiy <asta
 MODULE_DESCRIPTION("ACPI Battery Driver");
 MODULE_LICENSE("GPL");
 
+static int battery_bix_broken_package;
 static unsigned int cache_time = 1000;
 module_param(cache_time, uint, 0644);
 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
@@ -443,7 +444,12 @@ static int acpi_battery_get_info(struct
 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating %s", name));
 		return -ENODEV;
 	}
-	if (test_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags))
+
+	if (battery_bix_broken_package)
+		result = extract_package(battery, buffer.pointer,
+				extended_info_offsets + 1,
+				ARRAY_SIZE(extended_info_offsets) - 1);
+	else if (test_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags))
 		result = extract_package(battery, buffer.pointer,
 				extended_info_offsets,
 				ARRAY_SIZE(extended_info_offsets));
@@ -1054,6 +1060,17 @@ static int battery_notify(struct notifie
 	return 0;
 }
 
+static struct dmi_system_id bat_dmi_table[] = {
+	{
+		.ident = "NEC LZ750/LS",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "NEC"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "PC-LZ750LS"),
+		},
+	},
+	{},
+};
+
 static int acpi_battery_add(struct acpi_device *device)
 {
 	int result = 0;
@@ -1163,6 +1180,8 @@ static void __init acpi_battery_init_asy
 	if (!acpi_battery_dir)
 		return;
 #endif
+	if (dmi_check_system(bat_dmi_table))
+		battery_bix_broken_package = 1;
 	if (acpi_bus_register_driver(&acpi_battery_driver) < 0) {
 #ifdef CONFIG_ACPI_PROCFS_POWER
 		acpi_unlock_battery_dir(acpi_battery_dir);