From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mga14.intel.com ([143.182.124.37]:35675 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754438Ab3JBNot (ORCPT ); Wed, 2 Oct 2013 09:44:49 -0400 From: Sakari Ailus To: linux-media@vger.kernel.org Cc: hverkuil@xs4all.nl, laurent.pinchart@ideasonboard.com, teemux.tuominen@intel.com Subject: [RFC v2 3/4] v4l: vb2: Return POLLERR when polling for events and none are subscribed Date: Wed, 2 Oct 2013 16:45:15 +0300 Message-Id: <1380721516-488-4-git-send-email-sakari.ailus@linux.intel.com> In-Reply-To: <1380721516-488-1-git-send-email-sakari.ailus@linux.intel.com> References: <1380721516-488-1-git-send-email-sakari.ailus@linux.intel.com> Sender: linux-media-owner@vger.kernel.org List-ID: The current implementation allowed polling for events even if none were subscribed. This may be troublesome in multi-threaded applications where the thread handling the subscription is different from the one that handles the events. Signed-off-by: Sakari Ailus --- drivers/media/v4l2-core/videobuf2-core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index 79acf5e..c5dc903 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -2011,6 +2011,9 @@ unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait) if (v4l2_event_pending(fh)) res = POLLPRI; + + if (!v4l2_event_has_subscribed(fh)) + return POLLERR | POLLPRI; } if (!V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLIN | POLLRDNORM))) -- 1.8.3.2