From c3d6de698c84efdbdd3781b7058bcc339ab43da8 Mon Sep 17 00:00:00 2001
From: Thomas Renninger <trenn@suse.de>
Date: Fri, 1 Aug 2008 17:37:55 +0200
Subject: ACPI video: if no ACPI backlight support, use vendor drivers

If an ACPI graphics device supports backlight brightness functions (cmp. with
latest ACPI spec Appendix B), let the ACPI video driver control backlight and
switch backlight control off in vendor specific ACPI drivers (asus_acpi,
thinkpad_acpi, eeepc, fujitsu_laptop, msi_laptop, sony_laptop, acer-wmi).

Currently it is possible to load above drivers and let both poke on the
brightness HW registers, the video and vendor specific ACPI drivers -> bad.

This patch provides the basic support to check for BIOS capabilities before
driver loading time. Driver specific modifications are in separate follow up
patches.

"acpi_backlight=vendor"
	Prever vendor driver over ACPI driver for backlight.
"acpi_backlight=video" (default)
	Prever ACPI driver over vendor driver for backlight.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
---
 drivers/acpi/Makefile | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'drivers/acpi/Makefile')

diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index d91c027ece8..c03810aa19c 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -46,6 +46,10 @@ obj-$(CONFIG_ACPI_BUTTON)	+= button.o
 obj-$(CONFIG_ACPI_FAN)		+= fan.o
 obj-$(CONFIG_ACPI_DOCK)		+= dock.o
 obj-$(CONFIG_ACPI_VIDEO)	+= video.o
+ifdef CONFIG_ACPI_VIDEO
+obj-y				+= video_detect.o
+endif
+
 obj-y				+= pci_root.o pci_link.o pci_irq.o pci_bind.o
 obj-$(CONFIG_ACPI_PCI_SLOT)	+= pci_slot.o
 obj-$(CONFIG_ACPI_PROCESSOR)	+= processor.o
-- 
cgit