From: Chris Wilson <chris@chris-wilson.co.uk>
To: Keith Packard <keithp@keithp.com>,
jbarnes@virtuousgeek.org, intel-gfx@lists.freedesktop.org,
eric@anholt.net
Cc: Simon Que <sque@chromium.org>, bleung@chromium.org
Subject: Re: [PATCH] xf86-video-intel: change order of DPMS operations
Date: Thu, 08 Dec 2011 16:37:55 +0000 [thread overview]
Message-ID: <e39f63$2vffod@fmsmga002.fm.intel.com> (raw)
In-Reply-To: <86sjkv2f9b.fsf@sumi.keithp.com>
On Thu, 08 Dec 2011 08:35:12 -0800, Keith Packard <keithp@keithp.com> wrote:
> On Thu, 08 Dec 2011 14:10:06 +0000, Chris Wilson <chris@chris-wilson.co.uk> wrote:
>
> > I had to remind myself why both the driver and the kernel are both
> > touching the backlight across DPMS; the answer as I see it is that the
> > kernel only knows about the raw backlight interface whereas the driver
> > adjusts it via the preferred interface (which should handle the cases
> > where the backlight modulation is handled independently of the PWM
> > registers).
>
> Something in the kernel should be managing the backlight or we won't be
> doing this right when fbdev is running. User space should not have to
> know about the vagaries of the kernel backlight land.
The tricky part is figuring out the right interface to use. Matthew
was working upon such a mechanism to provide userspace with the ability
to actually find the backlight controller for a respective output, but I
don't believe there was ever a kernel API for i915 to call.
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
prev parent reply other threads:[~2011-12-08 16:38 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-08 0:20 [PATCH] xf86-video-intel: change order of DPMS operations Simon Que
2011-12-08 14:10 ` Chris Wilson
2011-12-08 16:35 ` Keith Packard
2011-12-08 16:37 ` Chris Wilson [this message]
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