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To:     Bjorn Helgaas <helgaas@kernel.org>
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From:   Logan Gunthorpe <logang@deltatee.com>
Message-ID: <bab9fb8b-1449-4b87-94de-7da26a279331@deltatee.com>
Date:   Thu, 1 Mar 2018 12:13:10 -0700
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Subject: Re: [PATCH v2 04/10] PCI/P2PDMA: Clear ACS P2P flags for all devices
 behind switches
Sender: linux-kernel-owner@vger.kernel.org
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On 01/03/18 11:02 AM, Bjorn Helgaas wrote:
>>   void pci_enable_acs(struct pci_dev *dev)
>>   {
>> +	if (pci_p2pdma_disable_acs(dev))
>> +		return;
> 
> This doesn't read naturally to me.  I do see that when
> CONFIG_PCI_P2PDMA is not set, pci_p2pdma_disable_acs() does nothing
> and returns 0, so we'll go ahead and try to enable ACS as before.
> 
> But I think it would be clearer to have an #ifdef CONFIG_PCI_P2PDMA
> right here so it's more obvious that we only disable ACS when it's
> selected.

I could do this... however, I wrote it this way because I've read Linus 
dislikes using #ifdef's inside function bodies and I personally agree 
with that sentiment.

Logan