From: Hans Verkuil <hans.verkuil@cisco.com>
Date: Wed, 13 Jul 2011 07:01:30 +0000 (-0300)
Subject: [media] videobuf2: only start streaming in poll() if so requested by the poll mask
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=bf5c7cbb996d6af51f8cc18a30ffa426196bf840;p=~shefty%2Frdma-dev.git

[media] videobuf2: only start streaming in poll() if so requested by the poll mask

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Pawel Osciak <pawel@osciak.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
---

diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c
index 2e8f1df775b..0b1c77114e8 100644
--- a/drivers/media/video/videobuf2-core.c
+++ b/drivers/media/video/videobuf2-core.c
@@ -1647,6 +1647,7 @@ static int __vb2_cleanup_fileio(struct vb2_queue *q);
  */
 unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
 {
+	unsigned long req_events = poll_requested_events(wait);
 	unsigned long flags;
 	unsigned int ret;
 	struct vb2_buffer *vb = NULL;
@@ -1655,12 +1656,14 @@ unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
 	 * Start file I/O emulator only if streaming API has not been used yet.
 	 */
 	if (q->num_buffers == 0 && q->fileio == NULL) {
-		if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ)) {
+		if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
+				(req_events & (POLLIN | POLLRDNORM))) {
 			ret = __vb2_init_fileio(q, 1);
 			if (ret)
 				return POLLERR;
 		}
-		if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE)) {
+		if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
+				(req_events & (POLLOUT | POLLWRNORM))) {
 			ret = __vb2_init_fileio(q, 0);
 			if (ret)
 				return POLLERR;