cpufreq: Allow drivers to advertise boost enabled

The behavior introduced in commit f37a4d6b ("cpufreq: Fix per-policy
boost behavior on SoCs using cpufreq_boost_set_sw()") sets up the boost
policy incorrectly when boost has been enabled by the platform firmware
initially even if a driver sets the policy up.

This is because policy_has_boost_freq() assumes that there is a frequency
table set up by the driver and that the boost frequencies are advertised
in that table. This assumption doesn't work for acpi-cpufreq or
amd-pstate. Only use this check to enable boost if it's not already
enabled instead of also disabling it if alreayd enabled.

Fixes: f37a4d6b ("cpufreq: Fix per-policy boost behavior on SoCs using cpufreq_boost_set_sw()")
Link: https://patch.msgid.link/20240626204723.6237-1-mario.limonciello@amd.comReviewed-by: Sibi Sankar <quic_sibis@quicinc.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Suggested-by: Viresh Kumar <viresh.kumar@linaro.org>
Suggested-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/cpufreq.c

@@ -1431,7 +1431,8 @@ static int cpufreq_online(unsigned int cpu)
 		}
 
 		/* Let the per-policy boost flag mirror the cpufreq_driver boost during init */
-		policy->boost_enabled = cpufreq_boost_enabled() && policy_has_boost_freq(policy);
+		if (cpufreq_boost_enabled() && policy_has_boost_freq(policy))
+			policy->boost_enabled = true;
 
 		/*
 		 * The initialization has succeeded and the policy is online.