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From: Henry Tseng <henrytseng@qnap.com>
To: "Rafael J. Wysocki" <rafael@kernel.org>,
	Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
	Len Brown <lenb@kernel.org>,
	Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-pm@vger.kernel.org, Henry Tseng <henrytseng@qnap.com>
Subject: [PATCH] cpufreq: intel_pstate: Use HYBRID_SCALING_FACTOR_ADL for Bartlett Lake
Date: Wed, 13 May 2026 18:28:46 +0800	[thread overview]
Message-ID: <20260513102847.75179-1-henrytseng@qnap.com> (raw)

Bartlett Lake P-core only SKUs (e.g. Intel Core 9 273PE)
do not report X86_FEATURE_HYBRID_CPU and are not in
intel_hybrid_scaling_factor[].  In hwp_get_cpu_scaling(), the
non-hybrid fallback then applies core_get_scaling() (100000),
producing cpuinfo_max_freq values that exceed the documented Max
Turbo Frequency:

  intel_pstate: CPU0: PERF_CTL turbo = 57
  intel_pstate: CPU0: HWP_CAP guaranteed = 30
  intel_pstate: CPU0: HWP_CAP highest = 70
  intel_pstate: CPU0: HWP-to-frequency scaling factor: 100000
  intel_pstate: set_policy cpuinfo.max 7000000 policy->max 7000000
  ...
  intel_pstate: CPU12: PERF_CTL turbo = 57
  intel_pstate: CPU12: HWP_CAP guaranteed = 30
  intel_pstate: CPU12: HWP_CAP highest = 73
  intel_pstate: CPU12: HWP-to-frequency scaling factor: 100000
  intel_pstate: set_policy cpuinfo.max 7300000 policy->max 7300000
  ...

Per the Intel datasheet [1], the Intel Core 9 273PE specifies:

  Performance-cores:                                 12
  Efficient-cores:                                   0
  Max Turbo Frequency:                               5.7 GHz
  Intel Thermal Velocity Boost Frequency:            5.7 GHz
  Intel Turbo Boost Max Technology 3.0 Frequency:    5.6 GHz
  Performance-core Max Turbo Frequency:              5.4 GHz
  Performance-core Base Frequency:                   2.3 GHz

Bartlett Lake P-cores are Raptor Cove cores, per
commit d466304c4322 ("x86/cpu: Add CPU model number for Bartlett
Lake CPUs with Raptor Cove cores").  The Alder Lake and Raptor Lake
P-core entries in intel_hybrid_scaling_factor[] use
HYBRID_SCALING_FACTOR_ADL (78741).  The same factor applies to
Bartlett Lake.

Add Bartlett Lake to intel_hybrid_scaling_factor[] with
HYBRID_SCALING_FACTOR_ADL so HWP performance levels map to the
correct CPU frequencies matching the datasheet's Max Turbo Frequency.

[1] https://www.intel.com/content/www/us/en/products/sku/245717/intel-core-9-processor-273pe-36m-cache-up-to-5-70-ghz/specifications.html

Signed-off-by: Henry Tseng <henrytseng@qnap.com>
---
 drivers/cpufreq/intel_pstate.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 1292da53e5fc..2737e51cff34 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -3734,6 +3734,7 @@ static const struct x86_cpu_id intel_hybrid_scaling_factor[] = {
 	X86_MATCH_VFM(INTEL_RAPTORLAKE, HYBRID_SCALING_FACTOR_ADL),
 	X86_MATCH_VFM(INTEL_RAPTORLAKE_P, HYBRID_SCALING_FACTOR_ADL),
 	X86_MATCH_VFM(INTEL_RAPTORLAKE_S, HYBRID_SCALING_FACTOR_ADL),
+	X86_MATCH_VFM(INTEL_BARTLETTLAKE, HYBRID_SCALING_FACTOR_ADL),
 	X86_MATCH_VFM(INTEL_METEORLAKE_L, HYBRID_SCALING_FACTOR_MTL),
 	X86_MATCH_VFM(INTEL_LUNARLAKE_M, HYBRID_SCALING_FACTOR_LNL),
 	{}
-- 
2.43.0


             reply	other threads:[~2026-05-13 10:29 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-13 10:28 Henry Tseng [this message]
2026-05-13 10:40 ` [PATCH] cpufreq: intel_pstate: Use HYBRID_SCALING_FACTOR_ADL for Bartlett Lake Rafael J. Wysocki
2026-05-14 10:17   ` Henry Tseng
2026-05-13 19:47 ` Rafael J. Wysocki

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