linux-kernel - [PATCH 15/15] cpufreq/amd-pstate: Set different default EPP policy for Epyc and Ryzen

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Message-ID: <20241205222847.7889-16-mario.limonciello@amd.com>
Date: Thu, 5 Dec 2024 16:28:47 -0600
From: Mario Limonciello <mario.limonciello@....com>
To: "Gautham R . Shenoy" <gautham.shenoy@....com>
CC: Perry Yuan <perry.yuan@....com>, <linux-kernel@...r.kernel.org>,
	<linux-pm@...r.kernel.org>, Dhananjay Ugwekar <Dhananjay.Ugwekar@....com>,
	Mario Limonciello <mario.limonciello@....com>, "Artem S . Tashkinov"
	<aros@....com>
Subject: [PATCH 15/15] cpufreq/amd-pstate: Set different default EPP policy for Epyc and Ryzen

For Ryzen systems the EPP policy set by the BIOS is generally configured
to performance as this is the default register value for the CPPC request
MSR.

If a user doesn't use additional software to configure EPP then the system
will default biased towards performance and consume extra battery. Instead
configure the default to "balanced_performance" for this case.

Suggested-by: Artem S. Tashkinov <aros@....com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219526
Signed-off-by: Mario Limonciello <mario.limonciello@....com>
---
 drivers/cpufreq/amd-pstate.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index b361e691fd33e..57775839a1c44 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -1503,8 +1503,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 
 	policy->driver_data = cpudata;
 
-	cpudata->epp_cached = cpudata->epp_default = amd_pstate_get_epp(cpudata);
-
 	policy->min = policy->cpuinfo.min_freq;
 	policy->max = policy->cpuinfo.max_freq;
 
@@ -1515,10 +1513,13 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 	 * the default cpufreq governor is neither powersave nor performance.
 	 */
 	if (amd_pstate_acpi_pm_profile_server() ||
-	    amd_pstate_acpi_pm_profile_undefined())
+	    amd_pstate_acpi_pm_profile_undefined()) {
 		policy->policy = CPUFREQ_POLICY_PERFORMANCE;
-	else
+		cpudata->epp_default = amd_pstate_get_epp(cpudata);
+	} else {
 		policy->policy = CPUFREQ_POLICY_POWERSAVE;
+		cpudata->epp_default = AMD_CPPC_EPP_BALANCE_PERFORMANCE;
+	}
 
 	if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
 		ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, &value);
@@ -1531,6 +1532,9 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 			return ret;
 		WRITE_ONCE(cpudata->cppc_cap1_cached, value);
 	}
+	ret = amd_pstate_set_epp(cpudata, cpudata->epp_default);
+	if (ret)
+		return ret;
 
 	current_pstate_driver->adjust_perf = NULL;
 
-- 
2.43.0