On Tue, 2009-04-07 at 13:57 +0800, Matthew Garrett wrote: > On Tue, Apr 07, 2009 at 11:45:11AM +0800, yakui_zhao wrote: > > On Sat, 2009-04-04 at 00:29 +0800, Matthew Garrett wrote: > > > Right. I'd imagine it as i915 loading and calling is_acpi_backlight(). > > > If that returns false, it should register a backlight device and also a > > > notifier. If a machine-specific platform device (like thinkpad_acpi or > > > dell_laptop or whatever) then loads, i915 should unregister its driver > > > and leave it up to the machine-specific one. The DDX would then use the > > > backlight device under all circumstances. > > A good idea. When there is no generic ACPI backlight I/F(_BQC/_BCL/_BCM) > > or platform backlight I/F, a new baclight I/F(using platform I2C > > command) will be registered in i915 driver. > > Will this new backlight I/F be registered in both UMS/KMS mode? > > 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? > > > But if we do so, it seems that we have to solve the dependency issue > > among acpi_video, i915 and platform driver. > > For example: I915 driver is loaded firstly and the interface will be > > registered. But after the acpi video driver/platform driver is loaded, > > how to send the notification event that i915 should unregister its > > interface? If the interface is unregistered, we will have to consider > > the arbiter order. > > 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? > > 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? > ------------------------------------------------------------------------------ This SF.net email is sponsored by: High Quality Requirements in a Collaborative Environment. Download a free trial of Rational Requirements Composer Now! http://p.sf.net/sfu/www-ibm-com -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
