From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp-vbr10.xs4all.nl ([194.109.24.30]:3112 "EHLO smtp-vbr10.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753447Ab3JBOIB (ORCPT ); Wed, 2 Oct 2013 10:08:01 -0400 Message-ID: <524C28B7.6080301@xs4all.nl> Date: Wed, 02 Oct 2013 16:07:51 +0200 From: Hans Verkuil MIME-Version: 1.0 To: Sakari Ailus CC: linux-media@vger.kernel.org, laurent.pinchart@ideasonboard.com, teemux.tuominen@intel.com Subject: Re: [RFC v2 2/4] v4l: vb2: Only poll for events if the user is interested in them References: <1380721516-488-1-git-send-email-sakari.ailus@linux.intel.com> <1380721516-488-3-git-send-email-sakari.ailus@linux.intel.com> In-Reply-To: <1380721516-488-3-git-send-email-sakari.ailus@linux.intel.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 10/02/13 15:45, Sakari Ailus wrote: > Also poll_wait() before checking the events since otherwise it's possible to > go to sleep and not getting woken up if the event arrives between the two > operations. > > Signed-off-by: Sakari Ailus > --- > drivers/media/v4l2-core/videobuf2-core.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c > index 594c75e..79acf5e 100644 > --- a/drivers/media/v4l2-core/videobuf2-core.c > +++ b/drivers/media/v4l2-core/videobuf2-core.c > @@ -2003,13 +2003,14 @@ unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait) > unsigned int res = 0; > unsigned long flags; > > - if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) { > + if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags) && > + req_events & POLLPRI) { Can you add parenthesis around 'req_events & POLLPRI'? When mixing '&&' and '&' that makes it more readable. > struct v4l2_fh *fh = file->private_data; > > + poll_wait(file, &fh->wait, wait); > + > if (v4l2_event_pending(fh)) > res = POLLPRI; > - else if (req_events & POLLPRI) > - poll_wait(file, &fh->wait, wait); > } > > if (!V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLIN | POLLRDNORM))) > After making that change you can add my: Acked-by: Hans Verkuil Regards, Hans