The following commit has been merged in the linux branch: commit 3a1151e3f124fd1a2c54b8153f510f1a7c715369 Author: Stefan Bader stefan.bader@canonical.com Date: Fri Aug 21 11:03:05 2009 +0200

ACPI: video: Loosen strictness of video bus detection code

BugLink: http://bugs.launchpad.net/bugs/333386

Currently a video bus device must (beside other criteria) define _DOD and _DOS methods to be considered a video device. Some broken BIOSes prevented working backlight control by only defining both for one (non-existing bus) and only _DOD for the rest. With this patch in place the other bus definitions were considered too and backlight control started to work again.

Signed-off-by: Stefan Bader stefan.bader@canonical.com Acked-by: Zhang Rui rui.zhang@intel.com Signed-off-by: Len Brown len.brown@intel.com

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index f6e54bf..64e3c58 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c @@ -1109,7 +1109,12 @@ static int acpi_video_bus_check(struct acpi_video_bus *video) */

/* Does this device support video switching? */ - if (video->cap._DOS) { + if (video->cap._DOS || video->cap._DOD) { + if (!video->cap._DOS) { + printk(KERN_WARNING FW_BUG + "ACPI(%s) defines _DOD but not _DOS\n", + acpi_device_bid(video->device)); + } video->flags.multihead = 1; status = 0; } diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c index 7032f25..575593a 100644 --- a/drivers/acpi/video_detect.c +++ b/drivers/acpi/video_detect.c @@ -84,7 +84,7 @@ long acpi_is_video_device(struct acpi_device *device) return 0;

/* Does this device able to support video switching ? */ - if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy)) && + if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy)) || ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy))) video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;