Re: [PATCH -next] iommu/arm-smmu-v3: Fix build error without CONFIG_PCI_ATS

[Yuehaibing]

On 2019/9/3 14:30, Will Deacon wrote:
> On Tue, Sep 03, 2019 at 10:42:12AM +0800, YueHaibing wrote:
>> If CONFIG_PCI_ATS is not set, building fails:
>>
>> drivers/iommu/arm-smmu-v3.c: In function arm_smmu_ats_supported:
>> drivers/iommu/arm-smmu-v3.c:2325:35: error: struct pci_dev has no member named ats_cap; did you mean msi_cap?
>>   return !pdev->untrusted && pdev->ats_cap;
>>                                    ^~~~~~~
>>
>> ats_cap should only used when CONFIG_PCI_ATS is defined,
>> so use #ifdef block to guard this.
>>
>> Fixes: bfff88ec1afe ("iommu/arm-smmu-v3: Rework enabling/disabling of ATS for PCI masters")
>> Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>
>> ---
>>  drivers/iommu/arm-smmu-v3.c | 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
>> index 66bf641..44ac9ac 100644
>> --- a/drivers/iommu/arm-smmu-v3.c
>> +++ b/drivers/iommu/arm-smmu-v3.c
>> @@ -2313,7 +2313,7 @@ static void arm_smmu_install_ste_for_dev(struct arm_smmu_master *master)
>>  
>>  static bool arm_smmu_ats_supported(struct arm_smmu_master *master)
>>  {
>> -	struct pci_dev *pdev;
>> +	struct pci_dev *pdev __maybe_unused;
>>  	struct arm_smmu_device *smmu = master->smmu;
>>  	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(master->dev);
>>  
>> @@ -2321,8 +2321,10 @@ static bool arm_smmu_ats_supported(struct arm_smmu_master *master)
>>  	    !(fwspec->flags & IOMMU_FWSPEC_PCI_RC_ATS) || pci_ats_disabled())
>>  		return false;
>>  
>> +#ifdef CONFIG_PCI_ATS
>>  	pdev = to_pci_dev(master->dev);
>>  	return !pdev->untrusted && pdev->ats_cap;
>> +#endif
>>  }
> 
> Hmm, I really don't like the missing return statement here, even though we
> never get this far thanks to the feature not getting set during ->probe().
> I'd actually prefer just to duplicate the function:
> 
> #ifndef CONFIG_PCI_ATS
> static bool
> arm_smmu_ats_supported(struct arm_smmu_master *master) { return false; }
> #else
> <current code here>
> #endif
> 
> Can you send a v2 like that, please?

Ok, will send v2 as your suggestion.

> 
> Will
> 
> .
>