[PATCH v1] cpufreq: intel_pstate: Always use HWP_DESIRED_PERF in passive mode

From: Rafael J. Wysocki
Date: Mon Jun 16 2025 - 14:19:31 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

In the passive mode, intel_cpufreq_update_pstate() sets HWP_MIN_PERF in
accordance with the target frequency to ensure delivering adequate
performance, but it sets HWP_DESIRED_PERF to 0, so the processor has no
indication that the desired performance level is actually equal to the
floor one. This may cause it to choose a performance point way above
the desired level.

Moreover, this is inconsistent with intel_cpufreq_adjust_perf() which
actually sets HWP_DESIRED_PERF in accordance with the target performance
value.

Address this by adjusting intel_cpufreq_update_pstate() to pass
target_pstate as both the minimum and the desired performance levels
to intel_cpufreq_hwp_update().

Fixes: a365ab6b9dfb ("cpufreq: intel_pstate: Implement the ->adjust_perf() callback")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/cpufreq/intel_pstate.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -3249,8 +3249,8 @@
int max_pstate = policy->strict_target ?
target_pstate : cpu->max_perf_ratio;

- intel_cpufreq_hwp_update(cpu, target_pstate, max_pstate, 0,
- fast_switch);
+ intel_cpufreq_hwp_update(cpu, target_pstate, max_pstate,
+ target_pstate, fast_switch);
} else if (target_pstate != old_pstate) {
intel_cpufreq_perf_ctl_update(cpu, target_pstate, fast_switch);
}