Hi Hans, Thank you for the patch. On Saturday 20 September 2014 10:56:14 Hans Verkuil wrote: > From: Hans Verkuil <hans.verkuil@xxxxxxxxx> > > Clarify what poll() returns if STREAMON was called but not QBUF. > Make explicit the different behavior for this scenario for > capture and output devices. > > Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> > --- > Documentation/DocBook/media/v4l/func-poll.xml | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/Documentation/DocBook/media/v4l/func-poll.xml > b/Documentation/DocBook/media/v4l/func-poll.xml index 85cad8b..b7ed9e8 > 100644 > --- a/Documentation/DocBook/media/v4l/func-poll.xml > +++ b/Documentation/DocBook/media/v4l/func-poll.xml > @@ -44,10 +44,18 @@ Capture devices set the <constant>POLLIN</constant> and > flags. When the function timed out it returns a value of zero, on > failure it returns <returnvalue>-1</returnvalue> and the > <varname>errno</varname> variable is set appropriately. When the > -application did not call &VIDIOC-QBUF; or &VIDIOC-STREAMON; yet the > +application did not call &VIDIOC-STREAMON; the > <function>poll()</function> function succeeds, but sets the > <constant>POLLERR</constant> flag in the > -<structfield>revents</structfield> field.</para> > +<structfield>revents</structfield> field. When the > +application calls &VIDIOC-STREAMON; for a capture device without a > +preceeding &VIDIOC-QBUF; the <function>poll()</function> function > +succeeds, but sets the <constant>POLLERR</constant> flag in the > +<structfield>revents</structfield> field. Nitpicking here, I would word it as When the application has called &VIDIOC-STREAMON; for a capture device but hasn't called &VIDIOC-QBUF; yet the <function>poll()</function> function succeeds and sets the <constant>POLLERR</constant> flag in the <structfield>revents</structfield> field. > For output devices this > +same situation will cause <function>poll()</function> to succeed > +as well, but it sets the <constant>POLLOUT</constant> and > +<constant>POLLWRNORM</constant> flags in the > <structfield>revents</structfield> > +field.</para> > > <para>When use of the <function>read()</function> function has > been negotiated and the driver does not capture yet, the -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
