linux-kernel - Re: [PATCH 3/5] cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support

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Date:   Fri, 18 Jun 2021 17:55:18 -0400
From:   Thara Gopinath <thara.gopinath@...aro.org>
To:     Bjorn Andersson <bjorn.andersson@...aro.org>
Cc:     agross@...nel.org, rui.zhang@...el.com, daniel.lezcano@...aro.org,
        viresh.kumar@...aro.org, rjw@...ysocki.net, robh+dt@...nel.org,
        linux-arm-msm@...r.kernel.org, linux-pm@...r.kernel.org,
        linux-kernel@...r.kernel.org, devicetree@...r.kernel.org
Subject: Re: [PATCH 3/5] cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support



On 6/18/21 2:16 PM, Bjorn Andersson wrote:
> On Tue 08 Jun 17:29 CDT 2021, Thara Gopinath wrote:
>> diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
> [..]
>> @@ -305,6 +383,8 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
>>   
>>   	index = args.args[0];
>>   
>> +	lmh_mitigation_enabled = of_property_read_bool(pdev->dev.of_node, "qcom,support-lmh");
> 
> Rather than adding a new interrupt _and_ a flag to tell the driver that
> this new interrupt should be used, wouldn't it be sufficient to just see
> if the interrupt is specified?

Yes. you are right. It should be. Though when I wrote it there was some 
reason which I forget now. I will remove it.

-- 
Warm Regards
Thara (She/Her/Hers)

> 
>> +
>>   	res = platform_get_resource(pdev, IORESOURCE_MEM, index);
>>   	if (!res) {
>>   		dev_err(dev, "failed to get mem resource %d\n", index);
>> @@ -329,6 +409,11 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
>>   		goto unmap_base;
>>   	}
>>   
>> +	if (!alloc_cpumask_var(&data->cpus, GFP_KERNEL)) {
>> +		ret = -ENOMEM;
>> +		goto unmap_base;
>> +	}
>> +
>>   	data->soc_data = of_device_get_match_data(&pdev->dev);
>>   	data->base = base;
>>   	data->res = res;
>> @@ -347,6 +432,7 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
>>   		goto error;
>>   	}
>>   
>> +	cpumask_copy(data->cpus, policy->cpus);
>>   	policy->driver_data = data;
>>   
>>   	ret = qcom_cpufreq_hw_read_lut(cpu_dev, policy);
>> @@ -370,6 +456,20 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
>>   			dev_warn(cpu_dev, "failed to enable boost: %d\n", ret);
>>   	}
>>   
>> +	if (lmh_mitigation_enabled) {
>> +		data->lmh_dcvs_irq = platform_get_irq(pdev, index);
>> +		if (data->lmh_dcvs_irq < 0) {
> 
> This will be -ENXIO if the interrupt isn't specified and <0 for other
> errors, so you should be able to distinguish the two failure cases.
> 
> Regards,
> Bjorn
> 
>> +			ret = data->lmh_dcvs_irq;
>> +			goto error;
>> +		}
>> +		ret = devm_request_irq(dev, data->lmh_dcvs_irq, qcom_lmh_dcvs_handle_irq,
>> +				       0, "dcvsh-irq", data);
>> +		if (ret) {
>> +			dev_err(dev, "Error %d registering irq %x\n", ret, data->lmh_dcvs_irq);
>> +			goto error;
>> +		}
>> +		INIT_DEFERRABLE_WORK(&data->lmh_dcvs_poll_work, qcom_lmh_dcvs_poll);
>> +	}
>>   	return 0;
>>   error:
>>   	kfree(data);
>> -- 
>> 2.25.1
>>