On 3 March 2015 at 17:11, Kapileshwar Singh <kapileshwar.si...@arm.com> wrote:
> Yes I indeed tested the case where we cache the device pointer of the CPU for
> which the OPP's are populated.
> When this CPU is hotplugged out, it invalidates the device pointer itself.
> Here are the error we get in dmesg:
What do you mean by 'invalidates the device pointer' ? that cpu_dev is NULL ?
> <3>[67203.216774] opp_get_voltage: Invalid parameters
> <3>[67203.326774] opp_get_voltage: Invalid parameters
> <3>[67203.326774] opp_get_voltage: Invalid parameters
Have you handwritten them ? Why don't they precede with dev_pm_* ??
>
> Which happens because:
>
> unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
> {
> ..
> tmp_opp = rcu_dereference(opp);
> if (unlikely(IS_ERR_OR_NULL(tmp_opp)) || !tmp_opp->available)
> pr_err("%s: Invalid parameters\n", __func__);
This %s should print routine name ..
> else
> ..
>
> Which happens when
>
> opp = dev_pm_opp_find_freq_exact(cpufreq_device->cpu_dev, freq_hz,
> true);
>
> returns a an erroneous or NULL OPP or the opp is unavailable (in the above
> condition)
Please goto the depth of this thing, as I don't think it should happen.
Over that I was asking you if you have tested the solution Javi gave,
because OPPs
wouldn't have been initialized for other CPUs once policy->cpu goes down.
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