[Intel-gfx] [RFC] [intel-gfx] :The backlight issue when KMS is used

Matthew Garrett mjg59 at srcf.ucam.org
Tue Apr 7 09:38:45 CEST 2009

On Tue, Apr 07, 2009 at 03:25:23PM +0800, yakui_zhao wrote:
> On Tue, 2009-04-07 at 13:57 +0800, Matthew Garrett wrote:
> > No, since in UMS mode the X server handles the backlight registers.
> If so, there is no change about the backlight flowchart in UMS mode.
> And only when the KMS mode is used, a new backlight I/F is registered.
> Right?


> > The acpi case is uninteresting - acpi_video_backlight_support() doesn't 
> > require the acpi video driver. The platform driver case is more 
> > interesting, but the easiest solution is probably to add a notifier 
> > chain for backlight device add and have i915 unregister when a platform 
> > device registers.
> Yes. We will have to create the communication channel between backlight
> device and i915 driver. And when a backlight I/F is registered, we will
> have to check whether the backlight I/F in 915 should be unregistered. 
> Right? 
> Does this make the problem complex? 

Not really. It's not a lot of code.

> > I'm not sure what you mean by arbiter order?
> What I said is which backlight I/F should be selected if there exist
> multiple backlight I/F?

The platform-specific one.

Matthew Garrett | mjg59 at srcf.ucam.org

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