在 2025/7/21 21:27, Rafael J. Wysocki 写道:
On Mon, Jul 21, 2025 at 5:26 AM Jiayi Li <lijiayi@xxxxxxxxxx> wrote:This patch fixes an issue where _PPC frequency limits set by the BIOS failed to take effect due to incorrect call ordering. Previously, freq_qos_update_request() was being called before freq_qos_add_request(), causing the constraint updates to be ignored. With this fix, the frequency limits are now properly enforced as intended. The original initialization sequence was: cpufreq_policy_online() acpi_cpufreq_cpu_init() acpi_processor_get_platform_limit() freq_qos_update_request(&perflib_req) blocking_notifier_call_chain(...) acpi_processor_ppc_init() freq_qos_add_request(&perflib_req) The new sequence explicitly ensures: cpufreq_policy_online() acpi_cpufreq_cpu_init() acpi_processor_get_platform_limit() freq_qos_update_request(&perflib_req) blocking_notifier_call_chain(...) acpi_processor_ppc_init() freq_qos_add_request(&perflib_req) + acpi_processor_get_platform_limit() + freq_qos_update_request(&perflib_req) The critical change adds an immediate platform limit update after the QoS request is registered. This guarantees that the initial P-state constraint is applied before any subsequent updates, resolving the window where constraints could be applied out-of-order. Fixes: d15ce412737a ("ACPI: cpufreq: Switch to QoS requests instead of cpufreq notifier") Signed-off-by: Jiayi Li <lijiayi@xxxxxxxxxx> --- v1 -> v2: - Modify the commit. - Add pr->performance check in acpi_processor_ppc_init loop. --- --- drivers/acpi/processor_perflib.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c index 64b8d1e19594..56f2b8354d62 100644 --- a/drivers/acpi/processor_perflib.c +++ b/drivers/acpi/processor_perflib.c @@ -173,6 +173,9 @@ void acpi_processor_ppc_init(struct cpufreq_policy *policy) { unsigned int cpu; + if (ignore_ppc == 1) + return; + for_each_cpu(cpu, policy->related_cpus) { struct acpi_processor *pr = per_cpu(processors, cpu); int ret; @@ -180,6 +183,9 @@ void acpi_processor_ppc_init(struct cpufreq_policy *policy) if (!pr) continue; + if (!pr->performance) + continue; + /* * Reset performance_platform_limit in case there is a stale * value in it, so as to make it match the "no limit" QoS valueApplied, but I have consolidated the pr and pr->performance checks above. I have also made some changes in the subject and changelog. Thanks!
Thanks for the review!
@@ -193,6 +199,11 @@ void acpi_processor_ppc_init(struct cpufreq_policy *policy) if (ret < 0) pr_err("Failed to add freq constraint for CPU%d (%d)\n", cpu, ret); + + ret = acpi_processor_get_platform_limit(pr); + if (ret) + pr_err("Failed to update freq constraint for CPU%d (%d)\n", + cpu, ret); } } --
