diff options
authorMichael Karcher <>2011-02-12 01:40:16 +0100
committerRafael J. Wysocki <>2011-02-12 01:40:16 +0100
commited764e7ca042dbf4cc1c7f4e12cd842c7789f133 (patch)
parent2a5d24286e8bdafdc272b37ec5bdd9e977b3767c (diff)
ACPI / Video: Probe for output switch method when searching video devices.
This patch reverts one hunk of 677bd810eedce61edf15452491781ff046b92edc "ACPI video: remove output switching control", namely the removal of probing for _DOS/_DOD when searching for video devices. This is needed on some Fujitsu Laptops (at least S7110, P8010) for the ACPI backlight interface to work, as an these machines, neither ROM nor posting methods are available, and after removal of output switching, none of the caps triggers, which prevents the backlight search from being entered. Tested on a Fujitsu Lifebook S7110 and Fujitsu Lifebook P8010. This probably fixes for the people who have no entry in /sys/class/backlight. This is the complete list of public (starting with "_") methods implemented on the S7110, BIOS rev 1.34: \_SB_.PCI0.GFX0._ADR \_SB_.PCI0.GFX0._DOS \_SB_.PCI0.GFX0._DOD \_SB_.PCI0.GFX0.CRT._ADR \_SB_.PCI0.GFX0.CRT._DCS \_SB_.PCI0.GFX0.CRT._DGS \_SB_.PCI0.GFX0.CRT._DSS \_SB_.PCI0.GFX0.LCD._ADR \_SB_.PCI0.GFX0.LCD._BCL \_SB_.PCI0.GFX0.LCD._BCM \_SB_.PCI0.GFX0.LCD._BQC \_SB_.PCI0.GFX0.LCD._DCS \_SB_.PCI0.GFX0.LCD._DGS \_SB_.PCI0.GFX0.LCD._DSS \_SB_.PCI0.GFX0.LCD._PS0 \_SB_.PCI0.GFX0.LCD._PS3 \_SB_.PCI0.GFX0.TV._ADR \_SB_.PCI0.GFX0.TV._DCS \_SB_.PCI0.GFX0.TV._DGS \_SB_.PCI0.GFX0.TV._DSS \_SB_.PCI0.GFX0.DVI._ADR \_SB_.PCI0.GFX0.DVI._DCS \_SB_.PCI0.GFX0.DVI._DGS \_SB_.PCI0.GFX0.DVI._DSS Signed-off-by: Michael Karcher <> Acked-by: Zhang Rui <> Signed-off-by: Rafael J. Wysocki <>
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index 42d3d72dae85..5af3479714f6 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -82,6 +82,11 @@ long acpi_is_video_device(struct acpi_device *device)
if (!device)
return 0;
+ /* Is this device able to support video switching ? */
+ if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy)) ||
+ ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy)))
/* Is this device able to retrieve a video ROM ? */
if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy)))