On Fri, Feb 08, 2019 at 12:47:06PM +0100, Marek Szyprowski wrote: > Hi Sudeep, > > On 2019-02-08 12:00, Sudeep Holla wrote: > > On Thu, Feb 07, 2019 at 01:22:25PM +0100, Marek Szyprowski wrote: > >> Dear All, > >> > >> This is a scenario that triggers the above issue: > > [...] > >> 1. system disables non-boot cpu's at the end of system suspend procedure, > >> 2. this in turn deinitializes cpufreq drivers for the disabled cpus, > >> 3. early in the system resume procedure all cpus are got back to online > >> state, > >> 4. this in turn causes cpufreq to be initialized for the newly onlined > >> cpus, > >> 5. cpufreq-dt acquires all its resources (clocks, regulators) during > >> ->init() callback, > > This is strictly not just restricted to cpufreq-dt, but to any driver > > supporting multiple policies. So we need a generic fix not just > > cpufreq-dt specific. > > Could you point which other driver needs similar fix? Here in cpufreq-dt > the problem was caused by using regulator api (indirectly) from > ->init(). All other drivers, which have regulators support, are for old, > obsolete, uni-processor systems, which don't have the problem of > secondary cpu suspend during system suspend/resume cycle. > scmi_cpufreq for instance. We can fix that in driver my moving to polling to get cpufreq_get_rate, but we support both polling and interrupt based. We may wait for remote processor interrupt in get_rate. -- Regards, Sudeep
