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Date:   Thu, 25 Apr 2019 16:18:32 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Ian Abbott <abbotti@mev.co.uk>
Cc:     Christoph Hellwig <hch@lst.de>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        Jiri Slaby <jslaby@suse.com>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
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        "kernel-janitors@vger.kernel.org H Hartley Sweeten" 
        <hsweeten@visionengravers.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] dma-mapping: remove an unnecessary NULL check
Message-ID: <20190425141832.GA16643@lst.de>
References: <20190424142437.GA29490@mwanda> <20190424142743.GC20974@lst.de> <3142dc82-1d4c-5f01-678e-628038d86bd6@mev.co.uk>
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On Thu, Apr 25, 2019 at 03:13:49PM +0100, Ian Abbott wrote:
> So for comedi_isadma, we can just replace the NULL with a pointer to a 
> static dummy device with a 24-bit coherent mask?

It should be converted to a proper isa_driver, so that it gets a real
struct device.