From: Daniel Vetter <daniel@ffwll.ch>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Tomasz Stanislawski <t.stanislaws@samsung.com>,
Subash Patel <subashrp@gmail.com>,
dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org,
kyungmin.park@samsung.com, sakari.ailus@iki.fi,
airlied@redhat.com
Subject: Re: [Linaro-mm-sig] [RFCv2 PATCH 4/9] v4l: add buffer exporting via dmabuf
Date: Thu, 22 Mar 2012 15:26:08 +0100 [thread overview]
Message-ID: <20120322142608.GA21024@phenom.ffwll.local> (raw)
In-Reply-To: <2231087.KvxzldpGDu@avalon>
On Thu, Mar 22, 2012 at 03:07:18PM +0100, Laurent Pinchart wrote:
> > >> + * Contains data used for exporting a video buffer as DMABUF file
> > >> + * descriptor. Uses the same 'cookie' as mmap() syscall. All reserved
> > >> fields
> > >> + * must be set to zero.
> > >> + */
> > >> +struct v4l2_exportbuffer {
> > >> + __u32 fd;
> > >> + __u32 reserved0;
> > >
> > > Why is there a reserved field here ?
> >
> > +1 to Laurent. Any particular need for reserved0 and reserved[13] below?
> > I think one void user pointer is sufficient even for future need.
>
> I'd rather have more than one void user pointer, just in case. A couple of
> bytes won't be expensive, and they will save lots of hassle in the future if
> we need to add a couple of fields. I was just wondering why there was a
> reserved field between fd and mem_offset.
Quick comment from a random bystander: __u32 is not big enough for a void*
pointer from userspace ...
-Daniel
--
Daniel Vetter
Mail: daniel@ffwll.ch
Mobile: +41 (0)79 365 57 48
next prev parent reply other threads:[~2012-03-22 14:29 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-13 10:16 [RFCv2 PATCH 0/9] Integration of videobuf2 with dmabuf Tomasz Stanislawski
2012-03-13 10:16 ` [RFCv2 PATCH 1/9] v4l: vb2: fixes for DMABUF support Tomasz Stanislawski
2012-03-22 7:56 ` Laurent Pinchart
2012-03-13 10:17 ` [RFCv2 PATCH 2/9] v4l: vb2-dma-contig: update and code refactoring Tomasz Stanislawski
2012-03-22 9:27 ` Laurent Pinchart
2012-03-22 10:02 ` [RFCv2 PATCH 2/9 - 1/4] v4l: vb2-dma-contig: Shorten vb2_dma_contig prefix to vb2_dc Laurent Pinchart
2012-03-22 10:02 ` [RFCv2 PATCH 2/9 - 2/4] v4l: vb2-dma-contig: Reorder functions Laurent Pinchart
2012-03-22 10:02 ` [RFCv2 PATCH 2/9 - 3/4] v4l: vb2-dma-contig: Remove unneeded allocation context structure Laurent Pinchart
2012-03-22 10:02 ` [RFCv2 PATCH 2/9 - 4/4] v4l: vb2-dma-contig: update and code refactoring Laurent Pinchart
2012-03-22 10:50 ` [Linaro-mm-sig] " Laurent Pinchart
2012-03-22 13:36 ` Tomasz Stanislawski
2012-03-22 14:42 ` Laurent Pinchart
2012-03-22 14:52 ` Subash Patel
2012-03-22 16:18 ` Tomasz Stanislawski
2012-03-22 15:58 ` Tomasz Stanislawski
2012-03-27 15:01 ` Laurent Pinchart
2012-03-27 16:45 ` Jerome Glisse
2012-03-27 16:58 ` Laurent Pinchart
2012-03-22 13:42 ` [Linaro-mm-sig] [RFCv2 PATCH 2/9] " Subash Patel
2012-03-13 10:17 ` [RFCv2 PATCH 3/9] v4l: vb2: Add dma-contig allocator as dma_buf user Tomasz Stanislawski
2012-03-22 11:04 ` Laurent Pinchart
2012-03-26 15:53 ` Tomasz Stanislawski
2012-03-28 15:50 ` Laurent Pinchart
2012-03-13 10:17 ` [RFCv2 PATCH 4/9] v4l: add buffer exporting via dmabuf Tomasz Stanislawski
2012-03-18 21:47 ` Daniel Vetter
2012-03-22 11:16 ` Laurent Pinchart
2012-03-22 13:57 ` [Linaro-mm-sig] " Subash Patel
2012-03-22 14:07 ` Laurent Pinchart
2012-03-22 14:26 ` Daniel Vetter [this message]
2012-03-22 14:43 ` Laurent Pinchart
2012-03-22 14:59 ` Subash Patel
2012-03-22 15:09 ` Laurent Pinchart
2012-03-23 11:33 ` Tomasz Stanislawski
2012-03-27 10:21 ` Laurent Pinchart
2012-03-13 10:17 ` [RFCv2 PATCH 5/9] v4l: vb2: " Tomasz Stanislawski
2012-03-22 11:24 ` Laurent Pinchart
2012-03-23 11:50 ` Tomasz Stanislawski
2012-03-13 10:17 ` [RFCv2 PATCH 6/9] v4l: vb2-dma-contig: add support for DMABUF exporting Tomasz Stanislawski
2012-03-13 10:17 ` [RFCv2 PATCH 7/9] v4l: vb2-dma-contig: change map/unmap behaviour Tomasz Stanislawski
2012-03-22 12:15 ` Laurent Pinchart
2012-03-22 12:25 ` Daniel Vetter
2012-03-27 10:31 ` Laurent Pinchart
2012-03-13 10:17 ` [RFCv2 PATCH 8/9] v4l: fimc: integrate capture i-face with dmabuf Tomasz Stanislawski
2012-03-13 10:17 ` [RFCv2 PATCH 9/9] v4l: s5p-tv: mixer: integrate " Tomasz Stanislawski
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