On 28-07-17, 20:43, Joel Fernandes wrote:
On Thu, Jul 27, 2017 at 11:46 PM, Viresh Kumar viresh.kumar@linaro.org wrote:
On many platforms, CPUs can do DVFS across cpufreq policies. i.e CPU from policy-A can change frequency of CPUs belonging to policy-B.
This is quite common in case of ARM platforms where we don't configure any per-cpu register.
Add a flag to identify such platforms and update cpufreq_can_do_remote_dvfs() to allow remote callbacks if this flag is set.
Also enable the flag for cpufreq-dt driver which is used only on ARM platforms currently.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org
drivers/cpufreq/cpufreq-dt.c | 1 + include/linux/cpufreq.h | 18 ++++++++++++++++-- 2 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c index fef3c2160691..d83ab94d041a 100644 --- a/drivers/cpufreq/cpufreq-dt.c +++ b/drivers/cpufreq/cpufreq-dt.c @@ -274,6 +274,7 @@ static int cpufreq_init(struct cpufreq_policy *policy) transition_latency = CPUFREQ_ETERNAL;
policy->cpuinfo.transition_latency = transition_latency;
policy->dvfs_possible_from_any_cpu = true;
Are there also ARM hardware that may not support it?
I don't think so. ARM never had any per-cpu register interface which may break due to this.
If yes, wouldn't a saner thing to do be to keep default as false and read the property from DT for hardware that does support it and then set to true?
I would do it if required, but for now I don't think there are any such users of cpufreq-dt.
-- viresh