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From: Robert Morell <rmorell@nvidia.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Sumit Semwal <sumit.semwal@ti.com>,
	"linux@arm.linux.org.uk" <linux@arm.linux.org.uk>,
	"jesse.barker@linaro.org" <jesse.barker@linaro.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
	"linaro-mm-sig@lists.linaro.org" <linaro-mm-sig@lists.linaro.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"daniel@ffwll.ch" <daniel@ffwll.ch>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"linux-media@vger.kernel.org" <linux-media@vger.kernel.org>
Subject: Re: [Linaro-mm-sig] [RFC v2 1/2] dma-buf: Introduce dma buffer sharing mechanism
Date: Fri, 9 Dec 2011 14:50:56 -0800	[thread overview]
Message-ID: <20111209225056.GL7969@morell.nvidia.com> (raw)
In-Reply-To: <201112051718.48324.arnd@arndb.de>

On Mon, Dec 05, 2011 at 09:18:48AM -0800, Arnd Bergmann wrote:
> On Friday 02 December 2011, Sumit Semwal wrote:
> > This is the first step in defining a dma buffer sharing mechanism.
> 
[...]
> 
> > +	return dmabuf;
> > +}
> > +EXPORT_SYMBOL(dma_buf_export);
> 
> I agree with Konrad, this should definitely be EXPORT_SYMBOL_GPL,
> because it's really a low-level function that I would expect
> to get used by in-kernel subsystems providing the feature to
> users and having back-end drivers, but it's not the kind of thing
> we want out-of-tree drivers to mess with.

Is this really necessary?  If this is intended to be a
lowest-common-denominator between many drivers to allow buffer sharing,
it seems like it needs to be able to be usable by all drivers.

If the interface is not accessible then I fear many drivers will be
forced to continue to roll their own buffer sharing mechanisms (which is
exactly what we're trying to avoid here, needless to say).

- Robert

  parent reply	other threads:[~2011-12-09 22:51 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 buffer sharing mechanism 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
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     ` Robert Morell [this message]
2011-12-10 11:13       ` [Linaro-mm-sig] " 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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