From: Christoph Hellwig <hch@lst.de>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: obayashi.yoshimasa@socionext.com, sumit.garg@linaro.org,
hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
stable@vger.kernel.org, daniel.thompson@linaro.org
Subject: Re: DMA direct mapping fix for 5.4 and earlier stable branches
Date: Tue, 9 Feb 2021 10:36:42 +0100 [thread overview]
Message-ID: <20210209093642.GA1006@lst.de> (raw)
In-Reply-To: <YCJUgKDNVjJ4dUqM@kroah.com>
On Tue, Feb 09, 2021 at 10:23:12AM +0100, Greg KH wrote:
> > From the view point of ZeroCopy using DMABUF, is 5.4 not
> > mature enough, and is 5.10 enough mature ?
> > This is the most important point for judging migration.
>
> How do you judge "mature"?
>
> And again, if a feature isn't present in a specific kernel version, why
> would you think that it would be a viable solution for you to use?
I'm pretty sure dma_get_sgtable has been around much longer and was
supposed to work, but only really did work properly for arm32, and
for platforms with coherent DMA. I bet he is using non-coherent arm64,
and it would be broken for other drivers there as well if people did
test them, which they apparently so far did not.
next prev parent reply other threads:[~2021-02-09 9:40 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-09 6:09 DMA direct mapping fix for 5.4 and earlier stable branches Sumit Garg
2021-02-09 6:58 ` Greg Kroah-Hartman
2021-02-09 7:58 ` Sumit Garg
2021-02-09 8:04 ` Greg Kroah-Hartman
2021-02-09 9:05 ` obayashi.yoshimasa
2021-02-09 9:23 ` Greg KH
2021-02-09 9:36 ` Christoph Hellwig [this message]
2021-02-09 12:36 ` Sumit Garg
2021-02-09 12:45 ` Robin Murphy
2021-02-09 15:50 ` Christoph Hellwig
2021-02-09 10:19 ` obayashi.yoshimasa
2021-02-09 10:39 ` Greg KH
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