From: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
To: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: Huacai Chen <chenhc@lemote.com>, Christoph Hellwig <hch@lst.de>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Robin Murphy <robin.murphy@arm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Fuxin Zhang <zhangfx@lemote.com>,
linux-kernel@vger.kernel.org, Ralf Baechle <ralf@linux-mips.org>,
James Hogan <james.hogan@imgtec.com>,
linux-mips@linux-mips.org,
"James E . J . Bottomley" <jejb@linux.vnet.ibm.com>,
"Martin K . Petersen" <martin.petersen@oracle.com>,
linux-scsi@vger.kernel.org, Tejun Heo <tj@kernel.org>,
linux-ide@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH V8 5/5] libata: Align DMA buffer to dma_get_cache_alignment()
Date: Wed, 18 Oct 2017 20:54:22 +0100 [thread overview]
Message-ID: <20171018205422.7fc8cbce@alans-desktop> (raw)
In-Reply-To: <94f55c1e-7553-0fc8-124e-ac6df5ac10ce@cogentembedded.com>
> This function is called only for the PIO mode commands, so I doubt this is
> necessary...
That is true but there are platforms out there that issue disk level PIO
commands via DMA (or can do so). Indeed the Cyrix MediaGX could do that
in the 1990s but I never add support 8)
So I think it makes sense to allocate the buffers DMA aligned, but it
doesn't seem to explain the situation in this case and I think it would
be helpful to know what platform and ATA driver is tripping this and wny
they are the only people in the universe to have the problem.
Alan
next prev parent reply other threads:[~2017-10-18 19:54 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-17 8:05 [PATCH V8 1/5] dma-mapping: Rework dma_get_cache_alignment() Huacai Chen
2017-10-17 8:05 ` [PATCH V8 2/5] MIPS: Implement dma_map_ops::get_cache_alignment() Huacai Chen
2017-10-17 8:05 ` [PATCH V8 3/5] scsi: Align block queue to dma_get_cache_alignment() Huacai Chen
2017-10-19 15:10 ` Christoph Hellwig
2017-10-17 8:05 ` [PATCH V8 4/5] libsas: Align SMP req/resp " Huacai Chen
2017-10-17 11:55 ` Marek Szyprowski
2017-10-18 1:12 ` [PATCH V8 4/5] libsas: Align SMP req/resp todma_get_cache_alignment() 陈华才
2017-10-19 15:12 ` [PATCH V8 4/5] libsas: Align SMP req/resp to dma_get_cache_alignment() Christoph Hellwig
2017-10-20 0:04 ` kbuild test robot
2017-10-17 8:05 ` [PATCH V8 5/5] libata: Align DMA buffer " Huacai Chen
2017-10-17 9:43 ` Sergei Shtylyov
2017-10-18 1:06 ` [PATCH V8 5/5] libata: Align DMA buffer todma_get_cache_alignment() 陈华才
2017-10-18 19:54 ` Alan Cox [this message]
2017-10-18 13:03 ` [PATCH V8 5/5] libata: Align DMA buffer to dma_get_cache_alignment() Tejun Heo
2017-10-19 7:52 ` Matt Redfearn
2017-10-20 4:25 ` [PATCH V8 5/5] libata: Align DMA buffer todma_get_cache_alignment() 陈华才
2017-10-18 17:23 ` [PATCH V8 1/5] dma-mapping: Rework dma_get_cache_alignment() Mark Greer
2017-10-19 15:09 ` Christoph Hellwig
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