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Subject: Re: [Patch v2 7/9] cpufreq: tegra194: add OPP support and set
 bandwidth
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To:     Viresh Kumar <viresh.kumar@linaro.org>
CC:     <treding@nvidia.com>, <krzysztof.kozlowski@linaro.org>,
        <dmitry.osipenko@collabora.com>, <rafael@kernel.org>,
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        Sumit Gupta <sumitg@nvidia.com>
References: <20230220140559.28289-1-sumitg@nvidia.com>
 <20230220140559.28289-8-sumitg@nvidia.com>
 <20230222040317.r2p6zlbumazymluc@vireshk-i7>
From:   Sumit Gupta <sumitg@nvidia.com>
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On 22/02/23 09:33, Viresh Kumar wrote:
> External email: Use caution opening links or attachments
> 
> 
> On 20-02-23, 19:35, Sumit Gupta wrote:
>> +static int tegra_cpufreq_set_bw(struct cpufreq_policy *policy, unsigned long freq_khz)
>> +{
>> +     struct dev_pm_opp *opp;
>> +     struct device *dev;
>> +     int ret;
>> +
>> +     dev = get_cpu_device(policy->cpu);
>> +     if (!dev)
>> +             return -ENODEV;
>> +
>> +     opp = dev_pm_opp_find_freq_exact(dev, freq_khz * KHZ, true);
>> +     if (IS_ERR(opp))
>> +             return PTR_ERR(opp);
>> +
>> +     ret = dev_pm_opp_set_opp(dev, opp);
>> +     dev_pm_opp_put(opp);
> 
> What about dev_pm_opp_set_rate() instead ?
> 
>> +     return ret;
>> +}
> 
> --
> viresh

Tried using it and got below crash. It seems to be coming because we 
don't have clocks property within CPU node for SoC's having BPMP-FW.

  Unable to handle kernel NULL pointer dereference at virtual address 
000000000000002e
  ....
  Call trace:
   clk_round_rate+0x38/0xd8
   dev_pm_opp_set_rate+0xe4/0x1a8
   tegra194_cpufreq_set_target+0x74/0x88
   __cpufreq_driver_target+0x154/0x250
   cpufreq_online+0x7b4/0x9ac

Thanks,
Sumit