[PATCH v2 2/4] cppc_cpufreq: clarify support for coordination types

From: Ionela Voinescu
Date: Mon Dec 14 2020 - 07:41:01 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>
Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
Cc: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
drivers/cpufreq/cppc_cpufreq.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index 2700fc71d4e8..f15a44c8b6b7 100644
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -244,7 +244,7 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
struct cppc_cpudata *cpu_data = all_cpu_data[policy->cpu];
struct cppc_perf_caps *caps = &cpu_data->perf_caps;
unsigned int cpu = policy->cpu;
- int ret = 0;
+ int i, ret = 0;

cpu_data->cpu = cpu;
ret = cppc_get_perf_caps(cpu, caps);
@@ -281,9 +281,13 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
policy->transition_delay_us = cppc_cpufreq_get_transition_delay_us(cpu);
policy->shared_type = cpu_data->shared_type;

- if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
- int i;
-
+ 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 */
cpumask_copy(policy->cpus, cpu_data->shared_cpu_map);

for_each_cpu(i, policy->cpus) {
@@ -293,9 +297,10 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
memcpy(&all_cpu_data[i]->perf_caps, caps,
sizeof(cpu_data->perf_caps));
}
- } 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_debug("Unsupported CPU co-ord type: %d\n",
+ policy->shared_type);
return -EFAULT;
}

--
2.29.2.dirty