[PATCH 27/37] iommu/arm-smmu-v3: Register fault workqueue

[Yisheng Xie]

Hi Jean,

On 2018/3/21 21:24, Jean-Philippe Brucker wrote:
> Hi Yisheng,
> 
> On 19/03/18 11:03, Yisheng Xie wrote:
>> Hi Jean,
>>
>> [...]
>>> @@ -3168,6 +3260,13 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>>>  	if (ret)
>>>  		return ret;
>>>  
>>> +	if (smmu->features & (ARM_SMMU_FEAT_STALLS | ARM_SMMU_FEAT_PRI)) {
>>> +		smmu->faultq_nb.notifier_call = arm_smmu_flush_queues;
>>> +		ret = iommu_fault_queue_register(&smmu->faultq_nb);
>>> +		if (ret)
>>> +			return ret;
>>
>> I find a case here: CONFIG_IOMMU_FAULT=n, and smmu support feature STALLS or PRI,
>> the device probe will failed here, is this what we want?
> 
> Since CONFIG_ARM_SMMU_V3 selects CONFIG_IOMMU_FAULT, I don't think it
> can happen. 

But CONFIG_IOMMU_FAULT can be changed after select, maybe can make it as unchangeable.

Thanks
Yisheng

> I'm not sure what the best practices are, but I feel like it
> would be too much work to guard against config combinations that violate
> an explicit "select" in Kconfig
> 
> Thanks,
> Jean
> 
> .
>