On 17/03/16 15:37, Catalin Marinas wrote: > On Thu, Mar 17, 2016 at 09:49:51AM -0500, Timur Tabi wrote: [...] >> Keep in mind that on an ACPI system like ours, the boot loader (UEFI in our >> case) configures the system extensively. It does a lot of things that the >> kernel would normally do on a device tree system. For example, pin control >> is handled completely by UEFI. The kernel does not set the pin muxes or >> GPIO directions. That means we don't support dynamic pin muxing. Before >> the kernel is booted, the GPIO pins are fixed. > > And that's great. But you are mistaken in thinking that DT requires lots > of drivers in the kernel and prevents the firmware from doing sane > stuff. DT rather gained additional features out of necessity since the > firmware was not always doing a proper job at hardware initialisation. > A DT-enabled kernel does not impose restrictions on such firmware > features. With ACPI, the choice is not as wide and forces vendors to > look into their firmware story from a different angle (until they figure > the _DSD+PRP0001 out and we end up with DT emulated in ACPI). Or even worse, perverting the couple of things that were actually OK in ACPI by inventing a new layer of broken stuff: http://thread.gmane.org/gmane.linux.ports.arm.msm/17828 Once we've reached that level, _DSD fells all nice and cuddly. M. -- Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html