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Date: Fri, 3 Aug 2018 09:22:12 -0700
From: Matthew Wilcox <willy@infradead.org>
Subject: Re: [PATCH v2 2/9] dmapool: cleanup error messages
Message-ID: <20180803162212.GA4718@bombadil.infradead.org>
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To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Tony Battersby <tonyb@cybernetics.com>, Christoph Hellwig <hch@lst.de>, Marek Szyprowski <m.szyprowski@samsung.com>, Sathya Prakash <sathya.prakash@broadcom.com>, Chaitra P B <chaitra.basappa@broadcom.com>, Suganath Prabu Subramani <suganath-prabu.subramani@broadcom.com>, iommu@lists.linux-foundation.org, linux-mm <linux-mm@kvack.org>, linux-scsi <linux-scsi@vger.kernel.org>, MPT-FusionLinux.pdl@broadcom.com

On Fri, Aug 03, 2018 at 06:59:20PM +0300, Andy Shevchenko wrote:
> >>> I'm pretty sure this was created in an order to avoid bad looking (and
> >>> in some cases frightening) "NULL device *" part.
> 
> JFYI: git log --no-merges --grep 'NULL device \*'

I think those commits actually argue in favour of Tony's patch to remove
the special casing.  Is it really useful to create dma pools with a NULL
device?