Re: ACPI crash on lid close - SMP race?

From: Sergio Monteiro Basto
Date: Mon Nov 10 2008 - 12:27:10 EST


Hi, About this _DOS , I reported this problem a long time ago, which now
is on http://bugzilla.kernel.org/show_bug.cgi?id=6001
Could you put yours comment on it ?

On fedora stock kernel, appears one patch, (Now I see that you are the
author :) )

I tested your patch and it works for me !

linux-2.6-acpi-video-dos.patch
Disable ACPI video display switching by default

-- mjg59

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index bac2901..93b1a9e 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -1818,7 +1818,7 @@ static int acpi_video_bus_put_devices(struct acpi_video_bus *video)

static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
{
- return acpi_video_bus_DOS(video, 0, 0);
+ return acpi_video_bus_DOS(video, 3, 1);
}

static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)


On Mon, 2008-11-10 at 16:11 +0000, Matthew Garrett wrote:
> If the _DOS flag on my HP 2510p is set to 0 (ie, signal OS when screen
> notification is requested, don't change automatically) then it'll crash
> on random lid open/closes. The trace generally makes little sense and
> depends on the kernel version and phase of the moon. I'd ignored this as
> firmware brokenness up until lately, but since having _DOS set to 0 is
> the only way to get a notification when the display switch key is
> pressed on this machine I'd be interested in fixing it properly.
>
> Unfortunately, I've got no real idea what on earth is going on. The only
> clue I've found so far is that booting with maxcpus=1 leaves it working
> perfectly. What parts of the ACPI stack could be triggering this?
>
--
SÃrgio M. B.

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