Messages in this thread | | | Date | Tue, 6 Jan 2015 13:51:27 +0000 | Subject | Re: [PATCH v5 18/18] Documentation: ACPI for ARM64 | From | G Gregory <> |
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On 6 January 2015 at 11:20, Catalin Marinas <catalin.marinas@arm.com> wrote: > On Mon, Jan 05, 2015 at 08:16:30PM +0000, Arnd Bergmann wrote: >> On Monday 05 January 2015 13:13:02 Catalin Marinas wrote: >> > > since passing no DT tables to OS but >> > > acpi=force is missing is a corner case, we can do a follow up patch to >> > > fix that, does it make sense? >> > >> > Not entirely. Why would no dtb and no acpi=force be a corner case? I >> > thought this should be the default when only ACPI tables are passed, no >> > need for an additional acpi=force argument. >> >> We don't really support the case of only ACPI tables for now. The expectation >> is that you always have working DT support, at least for the next few years >> as ACPI features are ramping up, and without acpi=force it should not try >> to use ACPI at all. > > So if both DT and ACPI are present, just use DT unless acpi=force is > passed. So far I think we agree but what I want to avoid is always > mandating acpi=force even when the DT tables are missing (in the long > run). > > Now, what's preventing a vendor firmware from providing only ACPI > tables? Do we enforce it in some way (arm-acpi.txt, kernel warning etc.) > that both DT and ACPI are supported, or at least that dts files are > merged in the kernel first? > How do we tell the difference between a DT passed purely for booting purposes ie a skeleton DT. And one which actually has hardware description as this needs to be done before unpacking the DT.
Graeme
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