Applied. thanks, -Len On Thursday 13 September 2007 23:46, Zhang Rui wrote: > Subject: set _DOS to 0 by default > From: Zhang Rui <rui.zhang@xxxxxxxxx> > > Many ACPI machines currently reprogram the active display output > automatically when the user presses the display toggle switch on > the keyboard. However, this behavior violates the ACPI spec, > because the system modifies some graphics device registers. > > "_DOS = 1" means that BIOS will switch the display, and ACPI is > not aware of the display switch hotkey pressing. > > And "_DOS = 0" means that BIOS will not switch the display > but just notify ACPI instead. > > We set _DOS to 0 by default from now on because ACPI video driver > has the mechanism to notify the user space when the display toggle > switch is pressed, i.e. ACPI video driver can send the hotkey events > via the input layer. > And X can/should get this event and call the native video device > driver to do the actual display switch work. > > Note: formerly we set _DOS to 1 to let BIOS handle the display switch, > but this doesn't always work on all platforms even in console mode. > http://bugzilla.kernel.org/show_bug.cgi?id=6001 > > Note: with this patch applied, in console mode, hotkey pressing may not > work because ACPI only export the hotkey events to user space while > X is not running, so no action is taken for this event. > users may need to "echo 1 >/proc/acpi/video/xxx/DOS" so that they > can switch the display with the help of BIOS. > > Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx> > --- > drivers/acpi/video.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > Index: linux-2.6/drivers/acpi/video.c > =================================================================== > --- linux-2.6.orig/drivers/acpi/video.c > +++ linux-2.6/drivers/acpi/video.c > @@ -1754,7 +1754,7 @@ static int acpi_video_bus_put_devices(st > > static int acpi_video_bus_start_devices(struct acpi_video_bus *video) > { > - return acpi_video_bus_DOS(video, 1, 0); > + return acpi_video_bus_DOS(video, 0, 0); > } > > static int acpi_video_bus_stop_devices(struct acpi_video_bus *video) > - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
