On Tuesday, October 11, 2016 02:44:29 PM Mark Brown wrote: > On Tue, Oct 11, 2016 at 01:44:46AM +0200, Rafael J. Wysocki wrote: > > On Thu, Oct 6, 2016 at 11:37 PM, Mark Brown <broonie@xxxxxxxxxx> wrote: > > > > Personally I don't have that big a concern around per device > > > properties other than the need to go through yet another round of > > > churn for them (though it is just mechanical which will make it less > > > painful). I do worry when it goes to generic things and inter-device > > > relationships. > > > Well, that was my first reaction to this series, but then I thought > > "Let's see what can go wrong with this specifically" and then I > > couldn't find anything. > > > If you see something like that, please let me know, because I may be > > overlooking it, but otherwise I would prefer to focus on the technical > > side of things instead of wast^Hspending time on theoretical worries. > > My primary concern is the addition of what appear to be phandles > introduced as part of this patch set. The previous discussion had been > that we'd enable simple DT bindings which don't need inter-device > references and that those needed more careful study. This appears to > be changing that. Yes, it does, but why exactly do you think this is wrong? Is there any specific problem it creates that you can point to? > > >> And it is not an option for those boards to use DT in the firmware. > > > > There's nothing stopping these systems defining a DSD that contains a > > > DTB which overrides some or all of the ACPI if the system supports it > > > (or otherwise providing both system descriptions). The two can coexist > > > happily enough as arm64 has shown > > > I'm not sure to what extent it has shown that and even so, it doesn't > > mean this is a good idea. > > People seem reasonably happy with it so far, YMMV. > > > > and it seems like it ought to save a > > > whole lot of work especially around the bits that need inter device > > > links and are hence need some new ACPI bindings defining. > > > There is at least one major problem with this approach. If the ACPI > > part needs to point to anything in the DTB or if the DTB part needs to > > point to the ACPI part outside of it, there's no clean way that could > > be done. I actually am not aware of any way whatever, but if there > > are some, I kind of don't expect them to be pretty. > > The way ARM implements this is that you don't get the DT and ACPI > simultaneously, they're both present in the firmware and the OS picks > which one it wants to use at runtime. So for the boards I'm talking about ACPI is the only realistic choice. Thanks, Rafael
Attachment:
signature.asc
Description: This is a digitally signed message part.
