From: Christoph Hellwig <hch@lst.de>
To: "Maciej W. Rozycki" <macro@linux-mips.org>
Cc: Christoph Hellwig <hch@lst.de>,
Paul Burton <paul.burton@mips.com>,
iommu@lists.linux-foundation.org,
Marek Szyprowski <m.szyprowski@samsung.com>,
Robin Murphy <robin.murphy@arm.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-mips@linux-mips.org, linux-kernel@vger.kernel.org,
stable@vger.kernel.org
Subject: Re: [PATCH] MIPS: Fix `dma_alloc_coherent' returning a non-coherent allocation
Date: Thu, 1 Nov 2018 09:33:46 +0100 [thread overview]
Message-ID: <20181101083346.GA7136@lst.de> (raw)
In-Reply-To: <alpine.LFD.2.21.1811010523440.20378@eddie.linux-mips.org>
On Thu, Nov 01, 2018 at 07:54:24AM +0000, Maciej W. Rozycki wrote:
> Fix a MIPS `dma_alloc_coherent' regression from commit bc3ec75de545
> ("dma-mapping: merge direct and noncoherent ops") that causes a cached
> allocation to be returned on noncoherent cache systems.
>
> This is due to an inverted check now used in the MIPS implementation of
> `arch_dma_alloc' on the result from `dma_direct_alloc_pages' before
> doing the cached-to-uncached mapping of the allocation address obtained.
> The mapping has to be done for a non-NULL rather than NULL result,
> because a NULL result means the allocation has failed.
>
> Invert the check for correct operation then.
>
> Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
> Fixes: bc3ec75de545 ("dma-mapping: merge direct and noncoherent ops")
> Cc: stable@vger.kernel.org # 4.19+
Oops, yes this looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
next prev parent reply other threads:[~2018-11-01 17:35 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20180914095808.22202-1-hch@lst.de>
[not found] ` <20180914095808.22202-5-hch@lst.de>
[not found] ` <alpine.LFD.2.21.1810311414200.20378@eddie.linux-mips.org>
[not found] ` <alpine.LFD.2.21.1810311559590.20378@eddie.linux-mips.org>
[not found] ` <20181031203206.GA28337@lst.de>
[not found] ` <alpine.LFD.2.21.1810312043250.20378@eddie.linux-mips.org>
[not found] ` <20181101051359.GA4164@lst.de>
2018-11-01 7:54 ` [PATCH] MIPS: Fix `dma_alloc_coherent' returning a non-coherent allocation Maciej W. Rozycki
2018-11-01 8:33 ` Christoph Hellwig [this message]
2018-11-01 14:30 ` Maciej W. Rozycki
2018-11-05 18:10 ` Paul Burton
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