[PATCH 2/2] cpufreq: mediatek: Add MT8173 cpufreq driver

Viresh Kumar viresh.kumar at linaro.org
Wed Jun 24 01:56:58 PDT 2015


On 24-06-15, 16:44, Pi-Cheng Chen wrote:
> One reason to put those initialization and resource allocation in probe is
> that it's easier to handle the return value -PROBE_DEFER from clock
> and regulator framework when trying to get clocks and regulators
> consumed by cpufreq driver.

This is the sequence of events if you move these things to ->init().

- your driver's probe()
  -> cpufreq_register_driver()
    -> init()
      -> clk/reg get, failed, return -EPROBE_DEFER

And the failure here will be propagated to probe(). So, it should
work IMHO.

> The other reason is when the whole system is resuming from suspend,
> the other subsystem e.g. i2c on which cpufreq driver depends might not
> ready yet during cpufreq driver initialization. In this case, the cpufreq
> driver will be blocked when trying to get resources e.g. regulator on i2c
> bus, and the whole system will stuck for seconds.

That's something else you must investigate on. This dependency should
be resolved in some other way, I thought DT might have taken care of
such dependencies.

-- 
viresh



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