linux-kernel - [PATCH v1] cpufreq: intel_pstate: Improve printing of debug messages

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Message-ID: <8609836.T7Z3S40VBb@rafael.j.wysocki>
Date: Wed, 15 Oct 2025 15:50:56 +0200
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Linux PM <linux-pm@...r.kernel.org>
Cc: LKML <linux-kernel@...r.kernel.org>,
 Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
 Artem Bityutskiy <artem.bityutskiy@...ux.intel.com>
Subject: [PATCH v1] cpufreq: intel_pstate: Improve printing of debug messages

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

Some debug messages generated by intel_pstate on a given hybrid system
are only printed for some CPUs which is confusing, so modify the driver
to print them for all CPUs.  Also change those messages to avoid
printing local variable names in them.

Moreover, some debug messages printed by intel_pstate are quite hard
to understand without looking at the code printing them, so make them
somewhat clearer while at it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
 drivers/cpufreq/intel_pstate.c |   25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -575,13 +575,18 @@ static void intel_pstate_hybrid_hwp_adju
 	int scaling = cpu->pstate.scaling;
 	int freq;
 
-	pr_debug("CPU%d: perf_ctl_max_phys = %d\n", cpu->cpu, perf_ctl_max_phys);
-	pr_debug("CPU%d: perf_ctl_turbo = %d\n", cpu->cpu, perf_ctl_turbo);
-	pr_debug("CPU%d: perf_ctl_scaling = %d\n", cpu->cpu, perf_ctl_scaling);
+	pr_debug("CPU%d: PERF_CTL max_phys = %d\n", cpu->cpu, perf_ctl_max_phys);
+	pr_debug("CPU%d: PERF_CTL turbo = %d\n", cpu->cpu, perf_ctl_turbo);
+	pr_debug("CPU%d: PERF_CTL scaling = %d\n", cpu->cpu, perf_ctl_scaling);
 	pr_debug("CPU%d: HWP_CAP guaranteed = %d\n", cpu->cpu, cpu->pstate.max_pstate);
 	pr_debug("CPU%d: HWP_CAP highest = %d\n", cpu->cpu, cpu->pstate.turbo_pstate);
 	pr_debug("CPU%d: HWP-to-frequency scaling factor: %d\n", cpu->cpu, scaling);
 
+	if (scaling == perf_ctl_scaling)
+		return;
+
+	hwp_is_hybrid = true;
+
 	cpu->pstate.turbo_freq = rounddown(cpu->pstate.turbo_pstate * scaling,
 					   perf_ctl_scaling);
 	cpu->pstate.max_freq = rounddown(cpu->pstate.max_pstate * scaling,
@@ -1044,9 +1049,9 @@ static void hybrid_set_cpu_capacity(stru
 
 	topology_set_cpu_scale(cpu->cpu, arch_scale_cpu_capacity(cpu->cpu));
 
-	pr_debug("CPU%d: perf = %u, max. perf = %u, base perf = %d\n", cpu->cpu,
-		 cpu->capacity_perf, hybrid_max_perf_cpu->capacity_perf,
-		 cpu->pstate.max_pstate_physical);
+	pr_debug("CPU%d: capacity perf = %u, base perf = %u, sys max perf = %u\n",
+		 cpu->cpu, cpu->capacity_perf, cpu->pstate.max_pstate_physical,
+		 hybrid_max_perf_cpu->capacity_perf);
 }
 
 static void hybrid_clear_cpu_capacity(unsigned int cpunum)
@@ -2344,11 +2349,10 @@ static void intel_pstate_set_min_pstate(
 
 static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
 {
-	int perf_ctl_max_phys = pstate_funcs.get_max_physical(cpu->cpu);
 	int perf_ctl_scaling = pstate_funcs.get_scaling();
 
+	cpu->pstate.max_pstate_physical = pstate_funcs.get_max_physical(cpu->cpu);
 	cpu->pstate.min_pstate = pstate_funcs.get_min(cpu->cpu);
-	cpu->pstate.max_pstate_physical = perf_ctl_max_phys;
 	cpu->pstate.perf_ctl_scaling = perf_ctl_scaling;
 
 	if (hwp_active && !hwp_mode_bdw) {
@@ -2356,10 +2360,7 @@ static void intel_pstate_get_cpu_pstates
 
 		if (pstate_funcs.get_cpu_scaling) {
 			cpu->pstate.scaling = pstate_funcs.get_cpu_scaling(cpu->cpu);
-			if (cpu->pstate.scaling != perf_ctl_scaling) {
-				intel_pstate_hybrid_hwp_adjust(cpu);
-				hwp_is_hybrid = true;
-			}
+			intel_pstate_hybrid_hwp_adjust(cpu);
 		} else {
 			cpu->pstate.scaling = perf_ctl_scaling;
 		}