| Date | Fri, 12 Sep 2014 15:43:36 -0400 | From | Jon Masters <> | Subject | Re: [PATCH v4 05/18] ARM64 / ACPI: Introduce sleep-arm.c |
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On 09/12/2014 10:00 AM, Hanjun Guo wrote: > From: Graeme Gregory <graeme.gregory@linaro.org> > > ACPI 5.1 does not currently support S states for ARM64 hardware but > ACPI code will call acpi_target_system_state() for device power > managment, so introduce sleep-arm.c to allow other drivers to function > until S states are defined.
Aside: ACPI5.1 does define the Platform Communication Channel and CPC (Collaborative Processor Performance Control). Some details need to be fleshed out there for practical 64-bit ARMv8 server systems, but the underpinnings and mechanisms are in place in the 5.1 specification that can be built upon over time to achieve practical S-State equivalence.
Jon.
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