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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-12-29 00:21:49 +0300 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-12-30 21:10:02 +0300 |
| commit | c02d5feb6e2f60affc6ba8606d8d614c071e2ba6 (patch) | |
| tree | e2dc2f1e6bee6764053b1c5263757818fcba0aea | |
| parent | fbf757e55afbd8b4d36f4808a6ae9107afeb79f3 (diff) | |
| download | linux-c02d5feb6e2f60affc6ba8606d8d614c071e2ba6.tar.xz | |
ACPI: processor: perflib: Use the "no limit" frequency QoS
When _PPC returns 0, it means that the CPU frequency is not limited by
the platform firmware, so make acpi_processor_get_platform_limit()
update the frequency QoS request used by it to "no limit" in that case.
This addresses a problem with limiting CPU frequency artificially on
some systems after CPU offline/online to the frequency that corresponds
to the first entry in the _PSS return package.
Reported-by: Pratyush Yadav <ptyadav@amazon.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Pratyush Yadav <ptyadav@amazon.de>
Tested-by: Pratyush Yadav <ptyadav@amazon.de>
| -rw-r--r-- | drivers/acpi/processor_perflib.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c index 970f04a958cd..0da85fc2a7e4 100644 --- a/drivers/acpi/processor_perflib.c +++ b/drivers/acpi/processor_perflib.c @@ -53,6 +53,8 @@ static int acpi_processor_get_platform_limit(struct acpi_processor *pr) { acpi_status status = 0; unsigned long long ppc = 0; + s32 qos_value; + int index; int ret; if (!pr) @@ -72,17 +74,27 @@ static int acpi_processor_get_platform_limit(struct acpi_processor *pr) } } + index = ppc; + pr_debug("CPU %d: _PPC is %d - frequency %s limited\n", pr->id, - (int)ppc, ppc ? "" : "not"); + index, index ? "is" : "is not"); - pr->performance_platform_limit = (int)ppc; + pr->performance_platform_limit = index; if (ppc >= pr->performance->state_count || unlikely(!freq_qos_request_active(&pr->perflib_req))) return 0; - ret = freq_qos_update_request(&pr->perflib_req, - pr->performance->states[ppc].core_frequency * 1000); + /* + * If _PPC returns 0, it means that all of the available states can be + * used ("no limit"). + */ + if (index == 0) + qos_value = FREQ_QOS_MAX_DEFAULT_VALUE; + else + qos_value = pr->performance->states[index].core_frequency * 1000; + + ret = freq_qos_update_request(&pr->perflib_req, qos_value); if (ret < 0) { pr_warn("Failed to update perflib freq constraint: CPU%d (%d)\n", pr->id, ret); |