From: Christoph Hellwig <hch@lst.de>
To: Tomasz Figa <tfiga@chromium.org>
Cc: Linux Media Mailing List <linux-media@vger.kernel.org>,
Linux Doc Mailing List <linux-doc@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Sergey Senozhatsky <senozhatsky@chromium.org>,
"open list:IOMMU DRIVERS" <iommu@lists.linux-foundation.org>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Robin Murphy <robin.murphy@arm.com>,
Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH 8/8] WIP: add a dma_alloc_contiguous API
Date: Wed, 7 Oct 2020 14:24:18 +0200 [thread overview]
Message-ID: <20201007122418.GA31318@lst.de> (raw)
In-Reply-To: <CAAFQd5AtN-ykAF_2mAqGxVugeEegYxfYdS6gD4O3zCY1jznNYA@mail.gmail.com>
On Wed, Oct 07, 2020 at 02:21:43PM +0200, Tomasz Figa wrote:
> My initial feeling is that it should work, but we'll give you a
> definitive answer once we prototype it. :)
>
> We might actually give it a try in the USB HCD subsystem as well, to
> implement usb_alloc_noncoherent(), as an optimization for drivers
> which have to perform multiple random accesses to the URB buffers. I
> think you might recall discussing this by the way of the pwc and
> uvcvideo camera drivers.
Yes. I guess for usb the dma_alloc_noncoherent as-is in linux-next
might be better. So if you have the cycles please prototype it
either way, although for that we'd also need at least a
mmap_noncoherent method, and probaby a get_sgtable_noncoherent one.
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next prev parent reply other threads:[~2020-10-07 12:24 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-30 16:09 dma_alloc_pages / dma_alloc_noncoherent fixups Christoph Hellwig
2020-09-30 16:09 ` [PATCH 1/8] dma-mapping: remove the {alloc,free}_noncoherent methods Christoph Hellwig
2020-09-30 16:09 ` [PATCH 2/8] dma-mapping: document dma_{alloc,free}_pages Christoph Hellwig
2020-09-30 16:09 ` [PATCH 3/8] dma-direct check for highmem pages in dma_direct_alloc_pages Christoph Hellwig
2020-09-30 16:09 ` [PATCH 4/8] dma-direct: use __GFP_ZERO " Christoph Hellwig
2020-10-06 7:24 ` Hillf Danton
2020-09-30 16:09 ` [PATCH 5/8] dma-direct: factor out a dma_direct_alloc_from_pool helper Christoph Hellwig
2020-09-30 16:09 ` [PATCH 6/8] dma-direct: simplify the DMA_ATTR_NO_KERNEL_MAPPING handling Christoph Hellwig
2020-09-30 16:09 ` [PATCH 7/8] dma-iommu: remove __iommu_dma_mmap Christoph Hellwig
2020-09-30 16:09 ` [PATCH 8/8] WIP: add a dma_alloc_contiguous API Christoph Hellwig
2020-10-02 17:50 ` Tomasz Figa
2020-10-05 8:26 ` Christoph Hellwig
2020-10-06 20:56 ` Tomasz Figa
2020-10-07 6:21 ` Christoph Hellwig
2020-10-07 12:21 ` Tomasz Figa
2020-10-07 12:24 ` Christoph Hellwig [this message]
2020-10-14 13:20 ` Tomasz Figa
2020-10-14 15:03 ` David Laight
2020-11-09 14:53 ` Ricardo Ribalda
2020-11-10 9:25 ` Christoph Hellwig
2020-11-10 9:33 ` Ricardo Ribalda
2020-11-10 9:41 ` Christoph Hellwig
2020-11-10 9:50 ` Tomasz Figa
2020-11-10 9:57 ` Christoph Hellwig
2020-11-17 21:21 ` Ricardo Ribalda
2020-11-18 14:25 ` [PATCH] WIP! media: uvcvideo: Use dma_alloc_noncontiguos API Ricardo Ribalda
2020-11-24 11:35 ` Christoph Hellwig
2020-11-24 12:01 ` Ricardo Ribalda
2020-11-24 13:33 ` Christoph Hellwig
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