From: Arnd Bergmann <arnd@arndb.de>
To: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Hans Verkuil <hverkuil@xs4all.nl>,
Sakari Ailus <sakari.ailus@iki.fi>,
Linux Media Mailing List <linux-media@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH] [media] v4l2 core: return -ENOIOCTLCMD if an ioctl doesn't exist
Date: Mon, 27 Jun 2011 18:14:35 +0200 [thread overview]
Message-ID: <201106271814.36251.arnd@arndb.de> (raw)
In-Reply-To: <4E08A2E6.6020902@redhat.com>
On Monday 27 June 2011, Mauro Carvalho Chehab wrote:
> > The point is that the spec can easily be improved to make such 'NOP' operations
> > explicit, or to require that if a capability is present, then the corresponding
> > ioctl(s) must also be present. Things like that are easy to verify as well with
> > v4l2-compliance.
>
> We currently have more than 64 ioctl's. Adding a capability bit for each doesn't
> seem the right thing to do. Ok, some could be grouped, but, even so, there are
> drivers that implement the VIDIOC_G, but doesn't implement the corresponding VIDIO_S.
> So, I think we don't have enough available bits for doing that.
It shouldn't be too hard to do an ioctl command that returns a le_bitmask with the
ioctl command number as an index (0 to 91, currently), and the bit set for each
command that has the corresponding v4l2_ioctl_ops member filled for the device.
That would be an obvious way to query the operations, but I don't know if it's
useful.
Arnd
next prev parent reply other threads:[~2011-06-27 16:14 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-24 23:11 [PATCH] [media] v4l2 core: return -ENOIOCTLCMD if an ioctl doesn't exist Mauro Carvalho Chehab
2011-06-26 15:40 ` Sakari Ailus
2011-06-26 16:20 ` Mauro Carvalho Chehab
2011-06-26 17:13 ` Arnd Bergmann
2011-06-26 17:30 ` Mauro Carvalho Chehab
2011-06-26 18:20 ` Arnd Bergmann
2011-06-26 18:51 ` Mauro Carvalho Chehab
2011-06-26 19:52 ` Arnd Bergmann
2011-06-27 5:38 ` Hans Verkuil
2011-06-27 12:02 ` Sakari Ailus
2011-06-27 12:17 ` Hans Verkuil
2011-06-27 12:17 ` Hans Verkuil
2011-06-27 13:54 ` Mauro Carvalho Chehab
2011-06-27 14:56 ` Hans Verkuil
2011-06-27 15:33 ` Mauro Carvalho Chehab
2011-06-27 16:14 ` Arnd Bergmann [this message]
2011-06-27 16:42 ` Mauro Carvalho Chehab
2011-06-27 17:07 ` Hans Verkuil
2011-06-27 20:37 ` Mauro Carvalho Chehab
2011-06-27 20:48 ` Linus Torvalds
2011-06-28 6:04 ` Hans Verkuil
2011-06-28 16:05 ` Linus Torvalds
2011-06-28 16:42 ` Alan Cox
2011-06-28 16:50 ` Arnd Bergmann
2011-06-29 12:34 ` Mauro Carvalho Chehab
2011-06-27 15:12 ` Andy Walls
2011-06-27 15:12 ` Andy Walls
2011-06-27 15:24 ` Mauro Carvalho Chehab
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