cpufreq/amd-pstate: Fix a regression leading to EPP 0 after resume

JIRA: https://issues.redhat.com/browse/RHEL-106954

commit ba3319e
Author: Mario Limonciello (AMD) <superm1@kernel.org>
Date:   Tue Aug 26 00:27:47 2025 -0500

    cpufreq/amd-pstate: Fix a regression leading to EPP 0 after resume

    During the suspend sequence the cached CPPC request is destroyed
    with the expectation that it's restored during resume.  This assumption
    broke when the separate cache EPP variable was removed, and then it was
    broken again by commit 608a76b ("cpufreq/amd-pstate: Add support
    for the "Requested CPU Min frequency" BIOS option") which explicitly
    set it to zero during suspend.

    Remove the invalidation and set the value during the suspend call to
    update limits so that the cached variable can be used to restore on
    resume.

    Fixes: 608a76b ("cpufreq/amd-pstate: Add support for the "Requested CPU Min frequency" BIOS option")
    Fixes: b7a4115 ("cpufreq/amd-pstate: Invalidate cppc_req_cached during suspend")
    Reported-by: goldens <goldenspinach.rhbugzilla@gmail.com>
    Closes: https://community.frame.work/t/increased-power-usage-after-resuming-from-suspend-on-ryzen-7040-kernel-6-15-regression/
    Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2391221
    Tested-by: goldens <goldenspinach.rhbugzilla@gmail.com>
    Tested-by: Willian Wang <kernel@willian.wang>
    Reported-by: Vincent Mauirn <vincent.maurin.fr@gmail.com>
    Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219981
    Tested-by: Alex De Lorenzo <kernel@alexdelorenzo.dev>
    Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
    Link: https://lore.kernel.org/r/20250826052747.2240670-1-superm1@kernel.org
    Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>

Signed-off-by: Steve Best <sbest@redhat.com>

Author: sfbest

drivers/cpufreq/amd-pstate.c

@@ -1615,13 +1615,14 @@ static int amd_pstate_suspend(struct cpufreq_policy *policy)
 	 * min_perf value across kexec reboots. If this CPU is just resumed back without kexec,
 	 * the limits, epp and desired perf will get reset to the cached values in cpudata struct
 	 */
-	ret = amd_pstate_update_perf(policy, perf.bios_min_perf, 0U, 0U, 0U, false);
+	ret = amd_pstate_update_perf(policy, perf.bios_min_perf,
+				     FIELD_GET(AMD_CPPC_DES_PERF_MASK, cpudata->cppc_req_cached),
+				     FIELD_GET(AMD_CPPC_MAX_PERF_MASK, cpudata->cppc_req_cached),
+				     FIELD_GET(AMD_CPPC_EPP_PERF_MASK, cpudata->cppc_req_cached),
+				     false);
 	if (ret)
 		return ret;
 
-	/* invalidate to ensure it's rewritten during resume */
-	cpudata->cppc_req_cached = 0;
-
 	/* set this flag to avoid setting core offline*/
 	cpudata->suspended = true;