Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1383983

[PATCH] media: vb2: Fix regression on poll() for RW mode

Show all headers | View raw

When using a device is read/write mode, vb2 does not handle properly the
first select/poll operation. It allways return POLLERR.

The reason for this is that when this code has been refactored, some of
the operations have changed their order, and now fileio emulator is not
started by poll, due to a previous check.

Reported-by: Dimitrios Katsaros <patcherwork@gmail.com>
Cc: Junghak Sung <jh1009.sung@samsung.com>
Cc: stable@vger.kernel.org
Fixes: 49d8ab9feaf2 ("media] media: videobuf2: Separate vb2_poll()")
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
 drivers/media/v4l2-core/videobuf2-core.c | 8 ++++++++
 drivers/media/v4l2-core/videobuf2-v4l2.c | 8 --------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 5d016f496e0e..199c65dbe330 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -2298,6 +2298,14 @@ unsigned int vb2_core_poll(struct vb2_queue *q, struct file *file,
 		return POLLERR;
 
 	/*
+	 * For compatibility with vb1: if QBUF hasn't been called yet, then
+	 * return POLLERR as well. This only affects capture queues, output
+	 * queues will always initialize waiting_for_buffers to false.
+	 */
+	if (q->waiting_for_buffers && (req_events & (POLLIN | POLLRDNORM)))
+		return POLLERR;
+
+	/*
 	 * For output streams you can call write() as long as there are fewer
 	 * buffers queued than there are buffers available.
 	 */
diff --git a/drivers/media/v4l2-core/videobuf2-v4l2.c b/drivers/media/v4l2-core/videobuf2-v4l2.c
index 91f552124050..c9bad9ef2104 100644
--- a/drivers/media/v4l2-core/videobuf2-v4l2.c
+++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
@@ -818,14 +818,6 @@ unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
 			poll_wait(file, &fh->wait, wait);
 	}
 
-	/*
-	 * For compatibility with vb1: if QBUF hasn't been called yet, then
-	 * return POLLERR as well. This only affects capture queues, output
-	 * queues will always initialize waiting_for_buffers to false.
-	 */
-	if (q->waiting_for_buffers && (req_events & (POLLIN | POLLRDNORM)))
-		return POLLERR;
-
 	return res | vb2_core_poll(q, file, wait);
 }
 EXPORT_SYMBOL_GPL(vb2_poll);
-- 
2.8.0.rc3

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

[PATCH] media: vb2: Fix regression on poll() for RW mode Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> - 2016-04-21 11:20 +0200
  Re: [PATCH] media: vb2: Fix regression on poll() for RW mode Hans Verkuil <hverkuil@xs4all.nl> - 2016-04-22 11:20 +0200
    Re: [PATCH] media: vb2: Fix regression on poll() for RW mode Hans Verkuil <hverkuil@xs4all.nl> - 2016-04-22 12:00 +0200
    Re: [PATCH] media: vb2: Fix regression on poll() for RW mode Mauro Carvalho Chehab <mchehab@osg.samsung.com> - 2016-04-22 14:40 +0200
      Re: [PATCH] media: vb2: Fix regression on poll() for RW mode Hans Verkuil <hverkuil@xs4all.nl> - 2016-04-22 14:40 +0200
        Re: [PATCH] media: vb2: Fix regression on poll() for RW mode Mauro Carvalho Chehab <mchehab@osg.samsung.com> - 2016-04-22 16:30 +0200
          Re: [PATCH] media: vb2: Fix regression on poll() for RW mode Hans Verkuil <hverkuil@xs4all.nl> - 2016-04-22 16:40 +0200
            Re: [PATCH] media: vb2: Fix regression on poll() for RW mode Mauro Carvalho Chehab <mchehab@osg.samsung.com> - 2016-04-22 16:50 +0200
              Re: [PATCH] media: vb2: Fix regression on poll() for RW mode Hans Verkuil <hverkuil@xs4all.nl> - 2016-04-22 17:00 +0200
                Re: [PATCH] media: vb2: Fix regression on poll() for RW mode Mauro Carvalho Chehab <mchehab@osg.samsung.com> - 2016-04-22 17:30 +0200
                Re: [PATCH] media: vb2: Fix regression on poll() for RW mode Hans Verkuil <hverkuil@xs4all.nl> - 2016-04-22 18:50 +0200
                Re: [PATCH] media: vb2: Fix regression on poll() for RW mode Mauro Carvalho Chehab <mchehab@osg.samsung.com> - 2016-04-22 19:50 +0200
  Re: [PATCH] media: vb2: Fix regression on poll() for RW mode Mauro Carvalho Chehab <mchehab@osg.samsung.com> - 2016-04-22 14:20 +0200

csiph-web