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-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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