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

Wed Apr 4 03:13:01 PDT 2018

On 22/03/18 01:09, Yisheng Xie wrote:
> 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. Seems sensible, I don't see a reason to leave IOMMU_FAULT selectable
manually.

Thanks,
Jean