linux-kernel - Re: [PATCH] drm/kms: fix fbdev blanking regression

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 13 Jan 2010 15:01:00 -0500
From:	Alex Deucher <alexdeucher@...il.com>
To:	James Simmons <jsimmons@...radead.org>
Cc:	Jesse Barnes <jbarnes@...tuousgeek.org>,
	David John <davidjon@...ontk.org>,
	Johan Hovold <jhovold@...il.com>, linux-kernel@...r.kernel.org,
	Dave Airlie <airlied@...hat.com>,
	dri-devel@...ts.sourceforge.net
Subject: Re: [PATCH] drm/kms: fix fbdev blanking regression

On Wed, Jan 13, 2010 at 2:48 PM, James Simmons <jsimmons@...radead.org> wrote:
>
>> > > On 01/07/2010 12:42 AM, Johan Hovold wrote:
>> > > >> Yeap. The fix uncovered a bug in your driver. I haven't heard of
>> > > >> problems with the other drm drivers.
>> > > >>
>> > > >>> The backlight is handled via the DRI driver I assume. At least
>> > > >>> i9xx_crtc_dpms is called on powerdown.
>> > > >>
>> > > >> Can you post your dmesg and kernel config.
>> > >
>> > > [snip]
>> > >
>> > > Adding the Intel DRM people in CC as well. I have the same issue
>> > > with my GM45.
>> >
>> > Okay I looked at the code to figure out what is happening and why
>> > only this driver has problems. The problem is that the framebuffer
>> > layer expects the backlight to be a seperate device. The reason being
>> > is that some embedded systems will use a gpio backlight. That way
>> > power management for a graphics card/backlight has 3 seperate states.
>> > Currently the intel DRM driver treats the backlight as being apart of
>> > the encoder. Jesse do you have objections to having the intel driver
>> > expose a backlight device. The bonus of that is the user can also set
>> > the backlight levels.
>>
>> On Intel we usually expect the backlight to be exposed by ACPI or a
>> platform driver.  On recent platforms, the ACPI driver will actually
>> send requests to the gfx driver to do the actual register writes to
>> adjust the backlight, but it's still ACPI driven.
>>
>> Maybe we just need to wire up the fb backlight hooks appropriately?
>
> Yeap. I can have patch ready for you this weekend. I lack the hardware to
> test it tho. Never been able to find a intel pci card that is not built
> into the motherboard.

They don't exist, other than the old i740s.

Alex
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/