From: Christoph Hellwig <hch@infradead.org>
To: Tomasz Figa <tfiga@chromium.org>
Cc: Christoph Hellwig <hch@infradead.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Nicolas Boichat <drinkcat@chromium.org>,
Shik Chen <shik@chromium.org>,
Linux Media Mailing List <linux-media@vger.kernel.org>,
notify@kernel.org, Keiichi Watanabe <keiichiw@chromium.org>,
Ricky Liang <jcliang@chromium.org>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
lkml <linux-kernel@vger.kernel.org>,
Kieran Bingham <kieran.bingham@ideasonboard.com>,
Vlastimil Babka <vbabka@suse.cz>,
Christoph Lameter <cl@linux.com>,
Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: Re: [PATCH] media: uvcvideo: Use streaming DMA APIs to transfer buffers
Date: Mon, 27 Apr 2020 05:48:40 -0700 [thread overview]
Message-ID: <20200427124840.GA30327@infradead.org> (raw)
In-Reply-To: <CAAFQd5A3iazOo+MordCqKk4+5nfSOT-rFu1ypGXF+geRec0aow@mail.gmail.com>
On Tue, Apr 21, 2020 at 01:21:15PM +0200, Tomasz Figa wrote:
> On Thu, Feb 27, 2020 at 7:28 AM Tomasz Figa <tfiga@chromium.org> wrote:
> >
> > +Sergey Senozhatsky who's going to be looking into this.
> >
> > Hi Christoph,
> >
> > That said, I noticed that you also put a lot of effort into making the
> > NONCONSISTENT attribute more usable. Perhaps that's the way to go here
> > then? Of course we would need to make sure that the attribute is
> > handled properly on ARM and ARM64, which are the most affected
> > platforms. Right now neither handles them. The former doesn't use the
> > generic DMA mapping ops, while the latter does, but doesn't enable a
> > Kconfig option needed to allow generic inconsistent allocations.
> >
> > Any hints would be appreciated.
>
> Hi Christoph, would you have some time to check the above?
>
> Hi Catalin, Will, do you know why CONFIG_DMA_NONCOHERENT_CACHE_SYNC is
> not enabled on arm64?
NONCONSISTENT is still a mess, mostly because dma_cache_sync is such
a horrible API. I've been wanting to switch to the normal
sync_for_device / sync_for_cpu primitives instead. Let me see if I can
expedite that.
prev parent reply other threads:[~2020-04-27 12:48 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-02 13:12 [PATCH] media: uvcvideo: Use streaming DMA APIs to transfer buffers Shik Chen
2019-08-27 2:03 ` Tomasz Figa
2019-09-28 3:33 ` Nicolas Boichat
2019-09-30 8:23 ` Christoph Hellwig
2019-10-01 6:37 ` Christoph Hellwig
2020-02-27 6:28 ` Tomasz Figa
2020-04-21 11:21 ` Tomasz Figa
2020-04-27 12:48 ` Christoph Hellwig [this message]
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