On Tue 10 July 2012 14:26:11 Ezequiel Garcia wrote:
> Hi Hans,
>
> On Tue, Jul 10, 2012 at 3:39 AM, Hans Verkuil <hverkuil@xxxxxxxxx> wrote:
> > On Tue July 10 2012 05:17:41 Ezequiel Garcia wrote:
> >> Hey Mauro,
> >>
> >> On Fri, Jul 6, 2012 at 11:41 AM, Ezequiel Garcia <elezegarcia@xxxxxxxxx> wrote:
> >> > On Thu, Jul 5, 2012 at 9:01 PM, Mauro Carvalho Chehab
> >> > <mchehab@xxxxxxxxxx> wrote:
> >> >> Em 05-07-2012 19:36, Sylwester Nawrocki escreveu:
> >> >>> On 07/06/2012 12:11 AM, Mauro Carvalho Chehab wrote:
> >> >>>>> +static int vidioc_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
> >> >>>>> +{
> >> >>>>> + struct stk1160 *dev = video_drvdata(file);
> >> >>>>> +
> >> >>>>> + if (!stk1160_is_owner(dev, file))
> >> >>>>> + return -EBUSY;
> >> >>>>> +
> >> >>>>> + return vb2_dqbuf(&dev->vb_vidq, p, file->f_flags& O_NONBLOCK);
> >
> > Take a look at the latest videobuf2-core.h: I've added helper functions
> > that check the owner. You can probably simplify the driver code quite a bit
> > by using those helpers.
>
> Ok.
>
> >
> >> >>>>
> >> >>>> Why to use O_NONBLOCK here? it should be doing whatever userspace wants.
> >> >>>
> >> >>> This is OK, since the third argument to vb2_dqbuf() is a boolean indicating
> >> >>> whether this call should be blocking or not. And a "& O_NONBLOCK" masks this
> >> >>> information out from file->f_flags.
> >> >>
> >> >> Ah! OK then.
> >> >>
> >> >> It might be better to initialize it during vb2 initialization, at open,
> >> >> instead of requiring this argument every time vb_dqbuf() is called.
> >
> > You can't do this at open since the application can change the NONBLOCK mode
> > after open. So the current approach is correct.
>
> Yes, that sounds ok. Let's wait until Mauro returns from holiday to discuss this
> with him.
>
> Also, what do you think about current_norm usage?
Don't use it. Implement g_std instead. current_norm really doesn't add anything
useful, it is a bit too magical and it doesn't work if you have multiple nodes
that share the same std (e.g. video and vbi).
I'm removing it from existing drivers whenever I have the chance, and it will
eventually go away.
Regards,
Hans
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