On 07/04/13 11:30, Sascha Hauer wrote: > On Thu, Jul 04, 2013 at 10:11:31AM +0100, Russell King wrote: >> On Thu, Jul 04, 2013 at 10:58:17AM +0200, Sascha Hauer wrote: >>> On Thu, Jul 04, 2013 at 09:40:52AM +0100, Russell King wrote: >>>> 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. >>> >>> What you describe here is a forced clone mode. This could be described >>> in the devicetree so that a driver wouldn't start before all connected >>> displays (links) are present, but this should be limited to the affected >>> path, not to the whole componentized device. >> >> Okay, to throw a recent argument back at you: so what in this scenario >> if you have a driver for the fixed-mode device but not the other device? >> >> It's exactly the same problem which you were describing to Sebastian >> just a moment ago with drivers missing from the supernode approach - >> you can't start if one of those "forced clone" drivers is missing. > > Indeed, then you will see nothing on your display, but I rather make > this setup a special case than the rather usual case that we do not > have compiled in all drivers for all devices referenced in the > supernode.
The super-node links SoC internal devices that do not necessarily match with the subsystem driver. You have one single DRM driver exploiting several device nodes for a single video card. But you need one device node to hook the driver to. Sebastian
