quoted

From 5da43d2ee6c87dcf17fda34f0b50fe11b04a16bf Mon Sep 17 00:00:00 2001

From: "Lee, Chun-Yi" <jlee@suse.com>
Date: Tue, 20 Mar 2012 19:00:58 +0800
Subject: [PATCH] acer-wmi: add quirk table for video backlight vendor mode

There have some acer laptop have broken _BCM implemenation, the AML
code wrote value to EC register but firmware didn't change brighenss.

Fortunately, the brightness control works on those machines with
vendor mode. So, add quirk table for video backlight vendor mode
and unregister acpi video interface on those machines.

Tested on Acer TravelMate 4750

Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
---
 drivers/platform/x86/Kconfig    |    4 ++++
 drivers/platform/x86/acer-wmi.c |   38 +++++++++++++++++++++++++++++++++++---
 2 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 15dbd8c..fe3a494 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig

@@ -26,6 +26,10 @@ config ACER_WMI
 	depends on RFKILL || RFKILL = n
 	depends on ACPI_WMI
 	select INPUT_SPARSEKMAP
+	# Acer WMI depends on ACPI_VIDEO when ACPI is enabled
+	# but for select to work, need to select ACPI_VIDEO's dependencies, ick
+        select VIDEO_OUTPUT_CONTROL if ACPI
+        select ACPI_VIDEO if ACPI
 	---help---
 	  This is a driver for newer Acer (and Wistron) laptops. It adds
 	  wireless radio and bluetooth control, and on some laptops,

diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
index 1e5290b..984a7b5 100644
--- a/drivers/platform/x86/acer-wmi.c
+++ b/drivers/platform/x86/acer-wmi.c

@@ -43,6 +43,7 @@
 #include <linux/input/sparse-keymap.h>
 
 #include <acpi/acpi_drivers.h>
+#include <acpi/video.h>
 
 MODULE_AUTHOR("Carlos Corbacho");
 MODULE_DESCRIPTION("Acer Laptop WMI Extras Driver");

@@ -478,6 +479,33 @@ static struct dmi_system_id acer_quirks[] = {
 	{}
 };
 
+static int video_set_backlight_video_vendor(const struct dmi_system_id *d)
+{
+	interface->capability &= ~ACER_CAP_BRIGHTNESS;
+	pr_info("Brightness must be controlled by generic video driver\n");
+	return 0;
+}
+
+static const struct dmi_system_id video_vendor_dmi_table[] = {
+	{
+		.callback = video_set_backlight_video_vendor,
+		.ident = "Acer Aspire 4736",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 4736"),
+		},
+	},
+	{
+		.callback = video_set_backlight_video_vendor,
+		.ident = "Acer TravelMate 4750",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 4750"),
+		},
+	},
+	{}
+};
+
 /* Find which quirks are needed for a particular vendor/ model pair */
 static void find_quirks(void)
 {

@@ -1981,9 +2009,13 @@ static int __init acer_wmi_init(void)
 	set_quirks();
 
 	if (acpi_video_backlight_support()) {
-		interface->capability &= ~ACER_CAP_BRIGHTNESS;
-		pr_info("Brightness must be controlled by "
-		       "generic video driver\n");
+		if (dmi_check_system(video_vendor_dmi_table)) {
+			acpi_video_unregister();
+		} else {
+			interface->capability &= ~ACER_CAP_BRIGHTNESS;
+			pr_info("Brightness must be controlled by "
+				"acpi video driver\n");
+		}
 	}
 
 	if (wmi_has_guid(WMID_GUID3)) {