On Thu, Jul 04, 2013 at 10:33:07AM +0200, Sascha Hauer wrote: > On Wed, Jul 03, 2013 at 10:52:49AM +0100, Russell King wrote: > > > > Sorry but I'd like to say that this cannot be used commonly. Shouldn't you > > > > really consider Linux framebuffer or other subsystems? The above dtsi file > > > > is specific to DRM subsystem. And I think the dtsi file has no any > > > > dependency on certain subsystem so board dtsi file should be considered for > > > > all device drivers based on other subsystems: i.e., Linux framebuffer, DRM, > > > > and so no. So I *strongly* object to it. All we have to do is to keep the > > > > dtsi file as is, and to find other better way that can be used commonly in > > > > DRM. > > > > > > +1 for not encoding the projected usecase of the graphics subsystem into > > > the devicetree. Whether the two LCD controllers shall be used together > > > or separately should not affect the devicetree. devicetree is about > > > hardware description, not configuration. > > > > And if we listen to that argument, then this problem is basically > > impossible to solve sanely. > > > > Are we really saying that we have no acceptable way to represent > > componentized devices in DT? If that's true, then DT fails to represent > > quite a lot of ARM hardware, and frankly we shouldn't be using it. I > > can't believe that's true though. > > > > The problem is that even with an ASoC like approach, that doesn't work > > here because there's no way to know how many "components" to expect. > > That's what the "supernode" is doing - telling us what components group > > together to form a device. > > A componentized device never completes and it doesn't have to. A > componentized device can start once there is a path from an input > (crtc, i2s unit) to an output (connector, speaker). Wrong. Please read the example with the diagrams I gave. Consider what happens if you have two display devices connected to a single output, one which fixes the allowable mode and one which _can_ reformat the selected mode. If you go down that path, you risk driving the LCD panel with inappropriate timings which may damage it. -- Russell King _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
