From: Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
To: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
Subject: Re: amd_iommu fallback question
Date: Fri, 6 Apr 2018 20:23:29 +0200 [thread overview]
Message-ID: <20180406182329.GA15462@8bytes.org> (raw)
In-Reply-To: <20180405193612.GA12474-jcswGhMUV9g@public.gmane.org>
Hi Christoph,
On Thu, Apr 05, 2018 at 09:36:12PM +0200, Christoph Hellwig wrote:
> I've got a little question on the amd_iommu code, hope you (or someone
> else on the list) can answer it. Most of the dma_map_ops methods have
> a fallback for the case when get_domain() return -EINVAL, which basically
> duplicates the normal no-iommu implementation, with the map_sg method
> being and exception that always returns and error (return value of 0
> is an error for its calling convention). Is that an oversight? If yes
> so I wonder why it hasn't been caught yet. Or is the whole fallback
> code dead and can be removed?
Yeah, the fall-back code is basically dead since the amd driver uses
per-device dma_ops. It was just an oversight that it is not removed yet.
Joerg
prev parent reply other threads:[~2018-04-06 18:23 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-05 19:36 amd_iommu fallback question Christoph Hellwig
[not found] ` <20180405193612.GA12474-jcswGhMUV9g@public.gmane.org>
2018-04-06 18:23 ` Joerg Roedel [this message]
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