linux-kernel - [PATCH v1 2/2] cpufreq: intel_pstate: Drop ACPI

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Date:   Tue, 27 Dec 2022 20:52:36 +0100
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     Linux PM <linux-pm@...r.kernel.org>
Cc:     Pratyush Yadav <ptyadav@...zon.de>,
        LKML <linux-kernel@...r.kernel.org>,
        Linux ACPI <linux-acpi@...r.kernel.org>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
Subject: [PATCH v1 2/2] cpufreq: intel_pstate: Drop ACPI _PSS states table patching

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

After making acpi_processor_get_platform_limit() use the "no limit"
value for its frequency QoS request when _PPC returns 0, it is not
necessary to replace the frequency corresponding to the first _PSS
return package entry with the maximum turbo frequency of the given
CPU in intel_pstate_init_acpi_perf_limits() any more, so drop the
code doing that along with the comment explaining it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
 drivers/cpufreq/intel_pstate.c |   14 --------------
 1 file changed, 14 deletions(-)

Index: linux-pm/drivers/cpufreq/intel_pstate.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/intel_pstate.c
+++ linux-pm/drivers/cpufreq/intel_pstate.c
@@ -452,20 +452,6 @@ static void intel_pstate_init_acpi_perf_
 			 (u32) cpu->acpi_perf_data.states[i].control);
 	}
 
-	/*
-	 * The _PSS table doesn't contain whole turbo frequency range.
-	 * This just contains +1 MHZ above the max non turbo frequency,
-	 * with control value corresponding to max turbo ratio. But
-	 * when cpufreq set policy is called, it will call with this
-	 * max frequency, which will cause a reduced performance as
-	 * this driver uses real max turbo frequency as the max
-	 * frequency. So correct this frequency in _PSS table to
-	 * correct max turbo frequency based on the turbo state.
-	 * Also need to convert to MHz as _PSS freq is in MHz.
-	 */
-	if (!global.turbo_disabled)
-		cpu->acpi_perf_data.states[0].core_frequency =
-					policy->cpuinfo.max_freq / 1000;
 	cpu->valid_pss_table = true;
 	pr_debug("_PPC limits will be enforced\n");