Messages in this thread | | | Date | Tue, 13 Jul 2021 08:48:48 +0530 | From | Viresh Kumar <> | Subject | Re: [Patch v3 3/6] cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support |
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On 12-07-21, 21:18, Thara Gopinath wrote: > So I really need the interrupt to fire and then the timer to kick in and > take up the monitoring. I can think of introducing a variable is_disabled > which is updated and read under a spinlock. qcom_cpufreq_hw_cpu_exit can > hold the spinlock and set is_disabled to true prior to cancelling the work > queue or disabling the interrupt. Before re-enabling the interrupt or > re-queuing the work in qcom_lmh_dcvs_notify, is_disabled can be read and > checked.
Or you can make the lmh_dcvs_poll_work item a pointer and mark it NULL in exit, with proper locking etc.
> But does this problem not exist in target_index , fast_switch etc also ? One > cpu can be disabling and the other one can be updating the target right?
The race doesn't happen there as cpufreq_unregister_driver() takes care of stopping everything before removing the policy. To be more precise, governor's ->stop() function is responsible for making sure that frequency won't be updated any further.
-- viresh
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