From baa7ac7527ee3990007fb28b59ec1d73b922ddaa Mon Sep 17 00:00:00 2001

From: Henrique de Moraes Holschuh <hmh@hmh.eng.br>

Date: Mon, 9 Aug 2010 23:48:19 -0300

Subject: [PATCH] thinkpad-acpi: untangle ACPI/vendor backlight selection

acpi_video_backlight_support() already tells us if ACPI is handling

backlight control through the generic ACPI handle.  It is better to just

trust it.

While at it, adjust down a printk priority, and test earlier for

brightness_enable=0.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>

Signed-off-by: Matthew Garrett <mjg@redhat.com>

---

 Documentation/laptops/thinkpad-acpi.txt |    4 +++

 drivers/platform/x86/thinkpad_acpi.c    |   42 ++++++++++++++----------------

 2 files changed, 24 insertions(+), 22 deletions(-)

diff --git a/Documentation/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt

index fc15538..720ba04 100644

--- a/Documentation/laptops/thinkpad-acpi.txt

+++ b/Documentation/laptops/thinkpad-acpi.txt

@@ -1073,6 +1073,10 @@ ThinkPad-specific interface.  The driver will disable its native

 backlight brightness control interface if it detects that the standard

 ACPI interface is available in the ThinkPad.

+If you want to use the thinkpad-acpi backlight brightness control

+instead of the generic ACPI video backlight brightness control for some

+reason, you should use the acpi_backlight=vendor kernel parameter.

+

 The brightness_enable module parameter can be used to control whether

 the LCD brightness control feature will be enabled when available.

 brightness_enable=0 forces it to be disabled.  brightness_enable=1

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c

index 4bdb137..b383cc6 100644

--- a/drivers/platform/x86/thinkpad_acpi.c

+++ b/drivers/platform/x86/thinkpad_acpi.c

@@ -6313,28 +6313,6 @@ static int __init brightness_init(struct ibm_init_struct *iibm)

 	if (tp_features.bright_unkfw)

 		return 1;

-	if (tp_features.bright_acpimode) {

-		if (acpi_video_backlight_support()) {

-			if (brightness_enable > 1) {

-				printk(TPACPI_NOTICE

-				       "Standard ACPI backlight interface "

-				       "available, not loading native one.\n");

-				return 1;

-			} else if (brightness_enable == 1) {

-				printk(TPACPI_NOTICE

-				       "Backlight control force enabled, even if standard "

-				       "ACPI backlight interface is available\n");

-			}

-		} else {

-			if (brightness_enable > 1) {

-				printk(TPACPI_NOTICE

-				       "Standard ACPI backlight interface not "

-				       "available, thinkpad_acpi native "

-				       "brightness control enabled\n");

-			}

-		}

-	}

-

 	if (!brightness_enable) {

 		dbg_printk(TPACPI_DBG_INIT | TPACPI_DBG_BRGHT,

 			   "brightness support disabled by "

@@ -6342,6 +6320,26 @@ static int __init brightness_init(struct ibm_init_struct *iibm)

 		return 1;

 	}

+	if (acpi_video_backlight_support()) {

+		if (brightness_enable > 1) {

+			printk(TPACPI_INFO

+			       "Standard ACPI backlight interface "

+			       "available, not loading native one.\n");

+			return 1;

+		} else if (brightness_enable == 1) {

+			printk(TPACPI_WARN

+				"Cannot enable backlight brightness support, "

+				"ACPI is already handling it.  Refer to the "

+				"acpi_backlight kernel parameter\n");

+			return 1;

+		}

+	} else if (tp_features.bright_acpimode && brightness_enable > 1) {

+		printk(TPACPI_NOTICE

+			"Standard ACPI backlight interface not "

+			"available, thinkpad_acpi native "

+			"brightness control enabled\n");

+	}

+

 	/*

 	 * Check for module parameter bogosity, note that we

 	 * init brightness_mode to TPACPI_BRGHT_MODE_MAX in order to be

-- 

1.7.3.2