Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 25 Feb 2013 17:53:31 -0800
From:      matt <sendtomatt@gmail.com>
To:        John Baldwin <jhb@freebsd.org>
Cc:        freebsd-acpi@freebsd.org, freebsd-current@freebsd.org
Subject:   Re: Fixing X220 Video The Right Way
Message-ID:  <512C159B.3020707@gmail.com>
In-Reply-To: <201302251330.57034.jhb@freebsd.org>
References:  <512A6FFF.2060603@gmail.com> <201302251330.57034.jhb@freebsd.org>

next in thread | previous in thread | raw e-mail | index | archive | help
On 02/25/13 10:30, John Baldwin wrote:
>
> Is there a better place to "correct" the ACPI_PATH that gets stored in
> vgapci's ivar? Is there already a tunable I can use to fix this?
> vgapci's ivar is set by the PCI address.  Do you have multiple vgapci devices?
>
No, just one. I think that the DSDT is very creative on recent Lenovos
(read: broken). There are multiple video devices defined, with
"functional" calls that nonetheless don't work to actually do anything.
The acpi_get_handle() call in acpi_video returns a handle that has no
active outputs and doesn't have any control over the brightness. The
other path can control brightness.

Here's a related discussion on Linux, I'm not sure how much applies
other than the situation discussed:
http://comments.gmane.org/gmane.linux.acpi.devel/57228

The same thing happens on AGP thinkpads, I believe, based on Mitsuru
Iwasaki's comment a long time ago to an X220 thread.

Matt




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?512C159B.3020707>