Re: [PATCH] drm/kms: fix fbdev blanking regression
From: James Simmons
Date: Sat Jan 16 2010 - 11:02:39 EST
> > > 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?
I'm about to work up a patch And I noticed that drm-next and
drm-intel-next are very different. Which tree should I use? Second is it
possible for a card to support more than one backlight.
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