diff options
| author |   Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-12-28 22:21:49 +0100 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-08-03 10:22:46 +0200 |
| commit | cd031669682ec0c4653cfd223644e1ec98a80179 (patch) | |
| tree | 64735db71704be7b5629a8e75a8b57199d61272b | |
| parent | e8e93e2f017e5467912d0746aee58a1f3cf501eb (diff) | |
| download | linux-yocto-cd031669682ec0c4653cfd223644e1ec98a80179.tar.gz | |
ACPI: processor: perflib: Use the "no limit" frequency QoS
commit c02d5feb6e2f60affc6ba8606d8d614c071e2ba6 upstream.
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>
Tested-by: Hagar Hemdan <hagarhem@amazon.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 757a98f6d7a2..c1a815a47116 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); |