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 @@
*/
/* 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 @@
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;