[media] media: vb2: Fix regression on poll() for RW mode
When using a device is read/write mode, vb2 does not handle properly the
first select/poll operation.
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.
The reintroduced check to the core is enabled by a quirk flag, that
avoids this check by other subsystems like DVB.
Fixes: 49d8ab9feaf2 ("media] media: videobuf2: Separate vb2_poll()")
Reported-by: Dimitrios Katsaros <patcherwork@gmail.com>
Cc: Junghak Sung <jh1009.sung@samsung.com>
Cc: <stable@vger.kernel.org> # for v4.5 and up
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
diff --git a/drivers/media/v4l2-core/videobuf2-v4l2.c b/drivers/media/v4l2-core/videobuf2-v4l2.c
index 8da7470..7f366f1 100644
--- a/drivers/media/v4l2-core/videobuf2-v4l2.c
+++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
@@ -771,6 +771,12 @@
q->is_output = V4L2_TYPE_IS_OUTPUT(q->type);
q->copy_timestamp = (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK)
== V4L2_BUF_FLAG_TIMESTAMP_COPY;
+ /*
+ * 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.
+ */
+ q->quirk_poll_must_check_waiting_for_buffers = true;
return vb2_core_queue_init(q);
}
@@ -824,14 +830,6 @@
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);