On Tue, Dec 27, 2022 at 5:40 PM srinivas pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote: > > On Tue, 2022-12-27 at 16:38 +0100, Pratyush Yadav wrote: > > Hi Srinivas, > > > > On Sat, Dec 24 2022, srinivas pandruvada wrote: > > > > > On Fri, 2022-12-23 at 10:10 -0800, srinivas pandruvada wrote: > > > > Hi Pratyush, > > > > > > > > On Thu, 2022-12-22 at 11:39 +0100, Pratyush Yadav wrote: > > > > > > > > > > Hi Srinivas, > > > > > > > > > > On Wed, Dec 21 2022, srinivas pandruvada wrote: > > > > > > On Wed, 2022-12-21 at 16:52 +0100, Pratyush Yadav 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. > > > > > > > This > > > > > > > causes problems when ACPI processor driver tries to set > > > > > > > frequency > > > > > > > constraints. See patch 2 for more details. > > > > > > > > > > > I can reproduce on a Broadwell server platform. But not on a > > > > client > > > > system with acpi_ppc usage. > > > > > > > > Need to check what change broke this. > > > > > > When PPC limits enforcement changed to PM QOS, this broke. > > > Previously > > > acpi_processor_get_platform_limit() was not enforcing any limits. > > > It > > > was just setting variable. So any update done after > > > acpi_register_performance_state() call to pr->performance- > > > > states[ppc].core_frequency, was effective. > > > > > > We don't really need to call > > > ret = freq_qos_update_request(&pr->perflib_req, > > > pr->performance->states[ppc].core_frequency > > > * > > > 1000); > > > > > > if the PPC is not changed. When PPC is changed, this gets called > > > again, > > > so then we can call the above function to update cpufreq limit. > > > > > > The below change fixed for me. > > > > Right. > I think, this is the only change you require to fix this. In addition > set pr->performance_platform_limit = 0 in > acpi_processor_unregister_performance(). Not really, because if the limit is set to a lower frequency and then reset to _PSS[0], it needs to be set back to "no limit". I'll send a patch for that in a while.
