From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Vetter <daniel@ffwll.ch>,
"Semwal, Sumit" <sumit.semwal@ti.com>,
linux@arm.linux.org.uk, linux-kernel@vger.kernel.org,
dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org,
linux-mm@kvack.org, linux-media@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [Linaro-mm-sig] [RFC v2 1/2] dma-buf: Introduce dma buffer sharing mechanism
Date: Fri, 9 Dec 2011 14:24:05 +0000 [thread overview]
Message-ID: <20111209142405.6f371be6@pyramind.ukuu.org.uk> (raw)
In-Reply-To: <201112091413.03736.arnd@arndb.de>
> I still don't think that's possible. Please explain how you expect
> to change the semantics of the streaming mapping API to allow multiple
> mappers without having explicit serialization points that are visible
> to all users. For simplicity, let's assume a cache coherent system
I would agree. It's not just about barriers but in many cases where you
have multiple mappings by hardware devices the actual hardware interface
is specific to the devices. Just take a look at the fencing in TTM and
the graphics drivers.
Its not something the low level API can deal with, it requires high level
knowledge.
Alan
next prev parent reply other threads:[~2011-12-09 14:24 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-02 8:57 [RFC v2 0/2] Introduce DMA " Sumit Semwal
2011-12-02 8:57 ` [RFC v2 1/2] dma-buf: Introduce dma " Sumit Semwal
2011-12-02 17:11 ` Konrad Rzeszutek Wilk
2011-12-05 9:48 ` Semwal, Sumit
2011-12-05 17:18 ` Arnd Bergmann
2011-12-05 18:55 ` Daniel Vetter
2011-12-05 19:29 ` Arnd Bergmann
2011-12-05 20:58 ` Daniel Vetter
2011-12-05 22:04 ` Arnd Bergmann
2011-12-05 22:33 ` Daniel Vetter
2011-12-05 20:46 ` Rob Clark
2011-12-05 21:23 ` Daniel Vetter
2011-12-05 22:11 ` Rob Clark
2011-12-05 22:33 ` Daniel Vetter
2011-12-06 13:16 ` Arnd Bergmann
2011-12-06 15:28 ` Daniel Vetter
2011-12-07 13:27 ` Semwal, Sumit
2011-12-07 13:40 ` Arnd Bergmann
2011-12-08 21:44 ` [Linaro-mm-sig] " Daniel Vetter
2011-12-09 14:13 ` Arnd Bergmann
2011-12-09 14:24 ` Alan Cox [this message]
2011-12-10 4:01 ` Daniel Vetter
2011-12-12 16:48 ` Arnd Bergmann
2011-12-19 6:16 ` Semwal, Sumit
2011-12-20 15:41 ` Arnd Bergmann
2011-12-20 16:41 ` Rob Clark
2011-12-20 17:14 ` Daniel Vetter
2011-12-21 17:27 ` Arnd Bergmann
2011-12-21 19:04 ` Daniel Vetter
2011-12-23 10:00 ` Semwal, Sumit
2011-12-23 17:10 ` Rob Clark
2011-12-20 9:03 ` Sakari Ailus
2011-12-20 15:36 ` Arnd Bergmann
2012-01-01 20:53 ` Sakari Ailus
2012-01-01 23:12 ` Rob Clark
2011-12-13 13:33 ` Hans Verkuil
2011-12-05 22:09 ` Arnd Bergmann
2011-12-05 22:15 ` Rob Clark
2011-12-05 22:35 ` Rob Clark
2011-12-07 6:35 ` Semwal, Sumit
2011-12-07 10:11 ` Arnd Bergmann
2011-12-07 11:02 ` Semwal, Sumit
2011-12-07 11:34 ` Arnd Bergmann
2011-12-09 22:50 ` [Linaro-mm-sig] " Robert Morell
2011-12-10 11:13 ` Mauro Carvalho Chehab
2011-12-12 22:44 ` Robert Morell
2011-12-13 15:10 ` Arnd Bergmann
2011-12-20 2:05 ` Robert Morell
2011-12-20 14:29 ` Anca Emanuel
2012-01-09 6:20 ` InKi Dae
2012-01-09 8:10 ` Daniel Vetter
2012-01-09 8:11 ` [Linaro-mm-sig] " Dave Airlie
2012-01-09 10:10 ` InKi Dae
2012-01-09 10:27 ` Daniel Vetter
2012-01-09 12:06 ` InKi Dae
2012-01-09 16:02 ` Daniel Vetter
2012-01-09 15:17 ` Rob Clark
2012-01-10 1:34 ` InKi Dae
2012-01-10 2:14 ` Rob Clark
2012-01-10 6:09 ` Semwal, Sumit
2012-01-10 7:28 ` InKi Dae
2012-01-10 9:19 ` InKi Dae
2012-01-11 1:08 ` InKi Dae
2011-12-02 8:57 ` [RFC v2 2/2] dma-buf: Documentation for buffer sharing framework Sumit Semwal
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