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Subject: Re: [PATCH 4/5] dma-direct: implement complete bus_dma_mask handling
To:     Christoph Hellwig <hch@lst.de>
Cc:     iommu@lists.linux-foundation.org,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
References: <20180920185247.20037-1-hch@lst.de>
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 <967e98b1-99ab-8f95-4c89-6156ce489b93@arm.com>
 <20180927162737.GA11974@lst.de>
From:   Robin Murphy <robin.murphy@arm.com>
Message-ID: <b87ef7ac-81fc-c649-7ffb-73017ec99790@arm.com>
Date:   Thu, 27 Sep 2018 17:41:36 +0100
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On 27/09/18 17:27, Christoph Hellwig wrote:
> On Thu, Sep 27, 2018 at 05:14:56PM +0100, Robin Murphy wrote:
>>> This just seemed more readable to me than min_not_zero, but if others
>>> prefer min_not_zero I can switch.
>>
>> Nah, just checking whether there were any intentionally different
>> assumptions compared to the couple of other places in the patch where
>> min_not_zero() *is* used. If it's purely a style thing then no worries
>> (personally I'd have written it yet another way anyway).
> 
> I'm curious: how would you have written it?

Come to think of it, I actually already have, in iommu-dma:

	if (dev->bus_dma_mask)
		mask &= dev->bus_dma_mask;

but of course it's not so pretty for those cases where you don't already 
have the local variable ready to go.

Robin.