diff mbox series

cpufreq: intel_pstate: Add EPP default for Kaby Lake

Message ID 639429100.102270.1749493735270@email.ionos.com
State New
Headers show
Series cpufreq: intel_pstate: Add EPP default for Kaby Lake | expand

Commit Message

Joe Walter June 9, 2025, 6:28 p.m. UTC 
Hi Srinivas,
Thank you for the clarification and your patience with my questions. You're absolutely right that EPP is working correctly and is a user choice.
 
The issue I'm addressing is that Kaby Lake systems currently get a default EPP value that causes suboptimal performance (900MHz frequency lock under load), while users may not realize they need to manually adjust EPP settings.
 
My patch follows the existing pattern in the intel_epp_default[] table where other CPU families (Alder Lake, Sapphire Rapids, etc.) have optimized default EPP values set by the kernel.
 
This ensures Kaby Lake systems work well "out of the box" while still allowing users to override EPP settings as needed.
 
Is this the correct approach, or would you prefer a different solution for setting better defaults on Kaby Lake systems?
 
I apologize for the multiple emails on this issue - I wanted to make sure I understood the proper solution. This will be my final submission on this topic.
 
Thanks for your patience,
Joe Walter
diff mbox series

Patch

From 776a4483e8423570205f42768e510ad001050899 Mon Sep 17 00:00:00 2001
From: Joe Walter <joe.walter@codesensesolutions.com>
Date: Mon, 9 Jun 2025 11:15:05 -0700
Subject: [PATCH 1/1] cpufreq: intel_pstate: Add EPP default for Kaby Lake

Kaby Lake processors (family 6, model 158) experience frequency
scaling issues where the CPU gets locked at minimum frequency
(~900MHz) under load when using the default EPP value.

Testing on Dell Inspiron systems with i5-7300HQ shows that setting
EPP to HWP_EPP_BALANCE_PERFORMANCE (128) resolves the issue and
allows proper frequency scaling up to 3+ GHz.

This affects at least Dell Inspiron 7567 systems, and likely other
Kaby Lake laptops with similar power management configurations.

Reported-by: Joe Walter <joe.walter@codesensesolutions.com>
Tested-by: Joe Walter <joe.walter@codesensesolutions.com>
Fixes: (EPP frequency scaling issues on Kaby Lake)
Signed-off-by: Joe Walter <joe.walter@codesensesolutions.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 64587d318267..dc79dd626b67 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -3781,6 +3781,7 @@  static const struct x86_cpu_id intel_epp_default[] = {
 	X86_MATCH_VFM(INTEL_EMERALDRAPIDS_X, HWP_SET_DEF_BALANCE_PERF_EPP(32)),
 	X86_MATCH_VFM(INTEL_GRANITERAPIDS_X, HWP_SET_DEF_BALANCE_PERF_EPP(32)),
 	X86_MATCH_VFM(INTEL_GRANITERAPIDS_D, HWP_SET_DEF_BALANCE_PERF_EPP(32)),
+	X86_MATCH_VFM(INTEL_KABYLAKE, HWP_SET_DEF_BALANCE_PERF_EPP(128)),
 	X86_MATCH_VFM(INTEL_METEORLAKE_L, HWP_SET_EPP_VALUES(HWP_EPP_POWERSAVE,
 		      179, 64, 16)),
 	X86_MATCH_VFM(INTEL_ARROWLAKE, HWP_SET_EPP_VALUES(HWP_EPP_POWERSAVE,
-- 
2.48.1