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To:     Christoph Hellwig <hch@lst.de>
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References: <20210715164544.6827-1-logang@deltatee.com>
 <20210715164544.6827-17-logang@deltatee.com> <20210716063332.GD13345@lst.de>
From:   Logan Gunthorpe <logang@deltatee.com>
Message-ID: <82c0f8d8-9050-dcf7-d68d-93691878a6dd@deltatee.com>
Date:   Fri, 16 Jul 2021 10:17:58 -0600
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Subject: Re: [PATCH v1 16/16] dma-mapping: Disallow .map_sg operations from
 returning zero on error
Precedence: bulk


On 2021-07-16 12:33 a.m., Christoph Hellwig wrote:
> On Thu, Jul 15, 2021 at 10:45:44AM -0600, Logan Gunthorpe wrote:
>> @@ -194,6 +194,8 @@ static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
>>  	else
>>  		ents = ops->map_sg(dev, sg, nents, dir, attrs);
>>  
>> +	WARN_ON_ONCE(ents == 0);
> 
> Turns this into a negative error code while we're at it, just to keep
> the callers sane?
> 

Sure thing. All the feedback makes sense, we'll fix it up and send a v2
in due course.

Thanks,

Logan