[PATCH 6/8] cppc_cpufreq: clarify support for coordination types

From: Ionela Voinescu
Date: Thu Nov 05 2020 - 07:57:00 EST


The previous coordination type handling in the cppc_cpufreq init code
created some confusion: the comment mentioned "Support only SW_ANY for
now" while only the SW_ALL/ALL case resulted in a failure. The other
coordination types (HW_ALL/HW, NONE) were silently supported.

Clarify support for coordination types while describing in comments the
intended behavior.

Signed-off-by: Ionela Voinescu <ionela.voinescu@xxxxxxx>
Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
Cc: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
drivers/cpufreq/cppc_cpufreq.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index fd2daeb59b49..60ac7f8049b5 100644
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -363,11 +363,22 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
policy->transition_delay_us = cppc_cpufreq_get_transition_delay_us(cpu);
policy->shared_type = domain->shared_type;

- if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
+ switch (policy->shared_type) {
+ case CPUFREQ_SHARED_TYPE_HW:
+ case CPUFREQ_SHARED_TYPE_NONE:
+ /* Nothing to be done - we'll have a policy for each CPU */
+ break;
+ case CPUFREQ_SHARED_TYPE_ANY:
+ /*
+ * All CPUs in the domain will share a policy and all cpufreq
+ * operations will use a single cppc_cpudata structure stored
+ * in policy->driver_data.
+ */
cpumask_copy(policy->cpus, domain->shared_cpu_map);
- } else if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL) {
- /* Support only SW_ANY for now. */
- pr_debug("Unsupported CPU co-ord type\n");
+ break;
+ default:
+ pr_info("Unsupported cpufreq CPU co-ord type: %d\n",
+ policy->shared_type);
return -EFAULT;
}

--
2.17.1