ACPI: processor: perflib: Avoid updating frequency QoS unnecessarily

stable inclusion
from stable-v5.10.190
commit a241fc02f1ce391da7b67d548a315dea575a9c6d
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I928UI

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a241fc02f1ce391da7b67d548a315dea575a9c6d



--------------------------------

commit 99387b01 upstream.

Modify acpi_processor_get_platform_limit() to avoid updating its
frequency QoS request when the _PPC return value has not changed
by comparing that value to the previous _PPC return value stored in
the performance_platform_limit field of the struct acpi_processor
corresponding to the given CPU.

While at it, do the _PPC return value check against the state count
earlier, to avoid setting performance_platform_limit to an invalid
value, and make acpi_processor_ppc_init() use FREQ_QOS_MAX_DEFAULT_VALUE
as the "no limit" frequency QoS for consistency.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Hagar Hemdan <hagarhem@amazon.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>