From: Sakari Ailus <sakari.ailus@iki.fi>
To: Scott Jiang <scott.jiang.linux@gmail.com>
Cc: Hans Verkuil <hverkuil@xs4all.nl>, LMML <linux-media@vger.kernel.org>
Subject: Re: about v4l2_fh_is_singular
Date: Tue, 20 Dec 2011 12:29:34 +0200 [thread overview]
Message-ID: <20111220102933.GP3677@valkosipuli.localdomain> (raw)
In-Reply-To: <CAHG8p1BZtAoYWu_-3sW1dtqwmATQbNSwcxZnEqYXsD8hdhcXUg@mail.gmail.com>
On Tue, Dec 20, 2011 at 05:29:47PM +0800, Scott Jiang wrote:
> Hi Sakari,
>
> Hans recommends me using v4l2_fh_is_singular in first open, but I
> found it used list_is_singular(&fh->list).
> Should it use &fh->vdev->fh_list or I missed something?
Hi, Scott!
I think why Hans is telling you that you should use v4l2_fh_is_singular()
instead of going for list_is_singular() directly, is that how the file
handles are being stored by the V4L2 subdev framework might be changed in
the future. If you use v4l2_fh_is_singular(), you won't need to change your
driver if that happens. Besides that, it's often better not deal with things
you don't really need to.
Regards,
--
Sakari Ailus
e-mail: sakari.ailus@iki.fi jabber/XMPP/Gmail: sailus@retiisi.org.uk
prev parent reply other threads:[~2011-12-20 10:29 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-20 9:29 about v4l2_fh_is_singular Scott Jiang
2011-12-20 10:29 ` Sakari Ailus [this message]
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