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authorTomi Valkeinen <tomi.valkeinen@ideasonboard.com>2021-04-12 13:02:09 +0200
committerMauro Carvalho Chehab <mchehab+huawei@kernel.org>2021-06-08 12:04:08 +0200
commita810ed0b3370e0b3f448233d526d085effd1f829 (patch)
tree2a78bd9d06cc2ba2a6e7186c2574e8aff5a4b02e /drivers/media/common
parentmedia: pci: tw5864: avoid usage of some characters (diff)
downloadlinux-a810ed0b3370e0b3f448233d526d085effd1f829.tar.xz
linux-a810ed0b3370e0b3f448233d526d085effd1f829.zip
media: videobuf2-v4l2.c: add vb2_queue_change_type() helper
On some platforms a video device can capture either video data or metadata. The driver can implement vidioc functions for both video and metadata, and use a single vb2_queue for the buffers. However, vb2_queue requires choosing a single buffer type, which conflicts with the idea of capturing either video or metadata. The buffer type of vb2_queue can be changed, but it's not obvious how this should be done in the drivers. To help this, add a new helper function vb2_queue_change_type() which ensures the correct checks and documents how it can be used. Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Diffstat (limited to 'drivers/media/common')
-rw-r--r--drivers/media/common/videobuf2/videobuf2-v4l2.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 7e96f67c60ba..2988bb38ceb1 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -939,6 +939,20 @@ void vb2_queue_release(struct vb2_queue *q)
}
EXPORT_SYMBOL_GPL(vb2_queue_release);
+int vb2_queue_change_type(struct vb2_queue *q, unsigned int type)
+{
+ if (type == q->type)
+ return 0;
+
+ if (vb2_is_busy(q))
+ return -EBUSY;
+
+ q->type = type;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_queue_change_type);
+
__poll_t vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
{
struct video_device *vfd = video_devdata(file);