From: Tomasz Figa <tfiga@chromium.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Marek Szyprowski <m.szyprowski@samsung.com>,
"open list:IOMMU DRIVERS" <iommu@lists.linux-foundation.org>,
Robin Murphy <robin.murphy@arm.com>,
Linux Doc Mailing List <linux-doc@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux Media Mailing List <linux-media@vger.kernel.org>
Subject: Re: [PATCH 8/8] WIP: add a dma_alloc_contiguous API
Date: Wed, 7 Oct 2020 14:21:43 +0200 [thread overview]
Message-ID: <CAAFQd5AtN-ykAF_2mAqGxVugeEegYxfYdS6gD4O3zCY1jznNYA@mail.gmail.com> (raw)
In-Reply-To: <20201007062150.GA10601@lst.de>
On Wed, Oct 7, 2020 at 8:21 AM Christoph Hellwig <hch@lst.de> wrote:
>
> On Tue, Oct 06, 2020 at 10:56:04PM +0200, Tomasz Figa wrote:
> > > Yes. And make sure the API isn't implemented when VIVT caches are
> > > used, but that isn't really different from the current interface.
> >
> > Okay, thanks. Let's see if we can make necessary changes to the videobuf2.
> >
> > +Sergey Senozhatsky for awareness too.
>
> I can defer the changes a bit to see if you'd really much prefer
> the former interface. I think for now the most important thing is
> that it works properly for the potential users, and the prime one is
> videobuf2 for now. drm also seems like a big potential users, but I
> had a really hard time getting the developers to engage in API
> development.
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.
Best regards,
Tomasz
next prev parent reply other threads:[~2020-10-07 12:22 UTC|newest]
Thread overview: 28+ 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
2020-09-30 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 [this message]
2020-10-07 12:24 ` Christoph Hellwig
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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