RE: [PATCH v10 1/2] cpufreq: Add Kryo CPU scaling driver

[ilialin]

> -----Original Message-----
> From: Sudeep Holla <sudeep.holla@xxxxxxx>
> Sent: Wednesday, May 23, 2018 13:40
> To: Ilia Lin <ilialin@xxxxxxxxxxxxxx>; vireshk@xxxxxxxxxx; nm@xxxxxx;
> sboyd@xxxxxxxxxx; robh@xxxxxxxxxx; mark.rutland@xxxxxxx;
> rjw@xxxxxxxxxxxxx; linux-pm@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx
> Cc: Sudeep Holla <sudeep.holla@xxxxxxx>
> Subject: Re: [PATCH v10 1/2] cpufreq: Add Kryo CPU scaling driver
> 
> 
> 
> On 23/05/18 10:40, Ilia Lin wrote:
> > In Certain QCOM SoCs like apq8096 and msm8996 that have KRYO
> > processors, the CPU frequency subset and voltage value of each OPP
> > varies based on the silicon variant in use. Qualcomm Process Voltage
> > Scaling Tables defines the voltage and frequency value based on the
> > msm-id in SMEM and speedbin blown in the efuse combination.
> > The qcom-cpufreq-kryo driver reads the msm-id and efuse value from the
> > SoC to provide the OPP framework with required information.
> > This is used to determine the voltage and frequency value for each OPP
> > of
> > operating-points-v2 table when it is parsed by the OPP framework.
> >
> > Signed-off-by: Ilia Lin <ilialin@xxxxxxxxxxxxxx>
> 
> [...]
> 
> > +	pdev = platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
> > +	if (!IS_ERR(pdev))
> > +		return 0;
> > +
> > +	ret = PTR_ERR(pdev);
> > +	dev_err(cpu_dev, "Failed to register platform device\n");
> > +
> > +free_opp:
> > +	for_each_possible_cpu(cpu) {
> > +		if (IS_ERR_OR_NULL(opp_tables[cpu]))
> > +			break;
> > +		dev_pm_opp_put_supported_hw(opp_tables[cpu]);
> > +	}
> > +free_np:
> > +	of_node_put(np);
> > +
> > +	return ret;
> > +}
> > +late_initcall(qcom_cpufreq_kryo_driver_init);
> 
> Any particular reason why this *has* to be late initcall ?
> Please change it to module_initcall otherwise.

The purpose is to give the cpufreq-dt the time to register the driver and only then my driver will add the platform device.

> Also address the of_node comments from Viresh.
> 
> Otherwise, it looks good.
> --
> Regards,
> Sudeep