On Sun, Jun 30, 2019 at 1:47 PM Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > > Hi Rob, > > Thank you for the patch. > > On Sun, Jun 30, 2019 at 01:36:04PM -0700, Rob Clark wrote: > > From: Rob Clark <robdclark@xxxxxxxxxxxx> > > > > Now that we can deal gracefully with bootloader (firmware) initialized > > display on aarch64 laptops[1], the next step is to deal with the fact > > that the same model of laptop can have one of multiple different panels. > > (For the yoga c630 that I have, I know of at least two possible panels, > > there might be a third.) > > I have to ask the obvious question: why doesn't the boot loader just > pass a correct DT to Linux ? There's no point in passing a list of > panels that are not there, this seems quite a big hack to me. A proper > boot loader should construct the DT based on hardware detection. Hi Laurent, Actually the bootloader on these devices is passing *no* dt (they boot ACPI, we are loading dtb from grub currently) I think normally a device built w/ dt in mind would populate /chosen/panel-id directly (rather than the way it is currently populated based on reading an efi variable prior to ExitBootServices). But that is considerably easier ask than having it re-write of_graph bindings. Either way, we aren't in control of the bootloader on these devices, so it is a matter of coming up with something that works on actual hw that we don't like rather than idealized hw that we don't have ;-) BR, -R
