cpufreq/amd-pstate: Invalidate cppc_req_cached during suspend

During resume it's possible the firmware didn't restore the CPPC request
MSR but the kernel thinks the values line up. This leads to incorrect
performance after resume from suspend.

To fix the issue invalidate the cached value at suspend. During resume use
the saved values programmed as cached limits.

Reviewed-by: Gautham R. Shenoy <[email protected]>
Reviewed-by: Dhananjay Ugwekar <[email protected]>
Reported-by: Miroslav Pavleski <[email protected]>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217931
Signed-off-by: Mario Limonciello <[email protected]>

Author: superm1

drivers/cpufreq/amd-pstate.c

@@ -1605,7 +1605,7 @@ static int amd_pstate_epp_reenable(struct cpufreq_policy *policy)
 					  max_perf, policy->boost_enabled);
 	}
 
-	return amd_pstate_update_perf(cpudata, 0, 0, max_perf, cpudata->epp_cached, false);
+	return amd_pstate_epp_update_limit(policy);
 }
 
 static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
@@ -1654,6 +1654,9 @@ static int amd_pstate_epp_suspend(struct cpufreq_policy *policy)
 	if (cppc_state != AMD_PSTATE_ACTIVE)
 		return 0;
 
+	/* invalidate to ensure it's rewritten during resume */
+	cpudata->cppc_req_cached = 0;
+
 	/* set this flag to avoid setting core offline*/
 	cpudata->suspended = true;