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authorRicardo Ribalda <ricardo.ribalda@gmail.com>2016-04-25 06:04:45 -0300
committerMauro Carvalho Chehab <mchehab@osg.samsung.com>2016-04-25 10:21:23 -0300
commitb93876845c5e30a92964eeb088d9d2e024118022 (patch)
tree1fe998001923b6f0a60bbdac1718cde4a1ce928a
parent3020ca711871fdaf0c15c8bab677a6bc302e28fe (diff)
[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>
-rw-r--r--drivers/media/v4l2-core/videobuf2-core.c10
-rw-r--r--drivers/media/v4l2-core/videobuf2-v4l2.c14
-rw-r--r--include/media/videobuf2-core.h4
3 files changed, 20 insertions, 8 deletions
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 2169544883e8..9fbcb67a9ee6 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -2298,6 +2298,16 @@ unsigned int vb2_core_poll(struct vb2_queue *q, struct file *file,
return POLLERR;
/*
+ * If this quirk is set and 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.
+ * This quirk is set by V4L2 for backwards compatibility reasons.
+ */
+ if (q->quirk_poll_must_check_waiting_for_buffers &&
+ 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 8da7470ca364..7f366f1b0377 100644
--- a/drivers/media/v4l2-core/videobuf2-v4l2.c
+++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
@@ -771,6 +771,12 @@ int vb2_queue_init(struct vb2_queue *q)
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 @@ 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);
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 5342ff4d748f..88e3ab496e8f 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -404,6 +404,9 @@ struct vb2_buf_ops {
* @fileio_read_once: report EOF after reading the first buffer
* @fileio_write_immediately: queue buffer after each write() call
* @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver
+ * @quirk_poll_must_check_waiting_for_buffers: Return POLLERR at poll when QBUF
+ * has not been called. This is a vb1 idiom that has been adopted
+ * also by vb2.
* @lock: pointer to a mutex that protects the vb2_queue struct. The
* driver can set this to a mutex to let the v4l2 core serialize
* the queuing ioctls. If the driver wants to handle locking
@@ -467,6 +470,7 @@ struct vb2_queue {
unsigned fileio_read_once:1;
unsigned fileio_write_immediately:1;
unsigned allow_zero_bytesused:1;
+ unsigned quirk_poll_must_check_waiting_for_buffers:1;
struct mutex *lock;
void *owner;

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