Messages in this thread | ![/](/images/icornerl.gif) | | From | "Rafael J. Wysocki" <> | Date | Tue, 27 Dec 2022 17:15:04 +0100 | Subject | Re: [PATCH 0/2] intel_pstate: fix turbo not being used after a processor is rebooted |
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On Wed, Dec 21, 2022 at 4:52 PM Pratyush Yadav <ptyadav@amazon.de> wrote: > > When a processor is brought offline and online again, it is unable to > use Turbo mode because the _PSS table does not contain the whole turbo > frequency range, but only +1 MHz above the max non-turbo frequency.
That's because of the way P-state limits in the turbo range are handled by the given processor.
Some of them restrict the P-state even if the limit is located within the turbo range and some of them don't (that is, requesting any P-state in the turbo range gives the processor a license to use the whole of it).
> This causes problems when ACPI processor driver tries to set frequency > constraints.
The problem is that acpi_processor_get_platform_limit() sets the limit to the frequency for all of the _PSS states including the last special one and it should update the QoS to "no limit" in that case.
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