[PATCH 0/3] media: uvcvideo: use vb2 ioctl and fop helpers

[PATCH 0/3] media: uvcvideo: use vb2 ioctl and fop helpers

[Ricardo Ribalda]

This is a rebump of a 4 years old patch from Hans.
https://lore.kernel.org/linux-media/20210618122923.385938-21-ribalda@chromium.org/

It brings "new" helpers to the uvcdriver and removes tons of code.

The first patch of this series is part of another series:
https://patchwork.linuxtv.org/project/linux-media/list/?series=15227

I have uploaded my working tree at:
https://gitlab.freedesktop.org/linux-media/users/ribalda/-/commits/b4/uvc-fop
which shows the differences from the original patch, this is mainly for
helping the review to people familiar with the previous patch.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
Hans Verkuil (1):
      media: uvcvideo: Use vb2 ioctl and fop helpers

Ricardo Ribalda (2):
      media: uvcvideo: Refactor uvc_queue_streamon
      media: uvcvideo: Remove stream->is_streaming field

 drivers/media/usb/uvc/uvc_driver.c   |  34 +----
 drivers/media/usb/uvc/uvc_metadata.c |   8 +-
 drivers/media/usb/uvc/uvc_queue.c    | 143 -------------------
 drivers/media/usb/uvc/uvc_v4l2.c     | 266 ++++-------------------------------
 drivers/media/usb/uvc/uvcvideo.h     |  38 +----
 5 files changed, 37 insertions(+), 452 deletions(-)
---
base-commit: 5e1ff2314797bf53636468a97719a8222deca9ae
change-id: 20250521-uvc-fop-b74e9007dd51

Best regards,
-- 
Ricardo Ribalda <ribalda@chromium.org>

[PATCH 1/3] media: uvcvideo: Refactor uvc_queue_streamon

[Ricardo Ribalda]

Do uvc_pm_get before we call uvc_queue_streamon. Although the current
code is correct, uvc_ioctl_streamon is allways called after uvc_pm_get,
this change makes the code more resiliant to future changes.

Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_v4l2.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 668a4e9d772c6d91f045ca75e2744b3a6c69da6b..862b4e34e5b629cf324479a9bb59ebe8784ccd5d 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -853,15 +853,16 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
 	if (handle->is_streaming)
 		return 0;
 
-	ret = uvc_queue_streamon(&stream->queue, type);
+	ret = uvc_pm_get(stream->dev);
 	if (ret)
 		return ret;
 
-	ret = uvc_pm_get(stream->dev);
+	ret = uvc_queue_streamon(&stream->queue, type);
 	if (ret) {
-		uvc_queue_streamoff(&stream->queue, type);
+		uvc_pm_put(stream->dev);
 		return ret;
 	}
+
 	handle->is_streaming = true;
 
 	return 0;

-- 
2.49.0.1151.ga128411c76-goog

[PATCH 2/3] media: uvcvideo: Use vb2 ioctl and fop helpers

[Ricardo Ribalda]

From: Hans Verkuil <hans@jjverkuil.nl>

When uvc was written the vb2 ioctl and file operation helpers didn't exist.

This patch switches uvc over to those helpers, which removes a lot of
boilerplatecode and simplifies VIDIOC_G/S_PRIORITY handling and allows us
to drop the 'privileges' scheme, since that's now handled inside the vb2
helpers.

This makes it possible for uvc to fix the v4l2-compliance streaming tests:
 warn: v4l2-test-formats.cpp(1075): Could not set fmt2

This patch introduces a change on behavior on the uvcdriver to be
aligned with the rest of the subsystem. Now S_INPUT, S_PARM and
S_FORMAT do no gran exclusive ownership of the device.

Signed-off-by: Hans Verkuil <hans@jjverkuil.nl>
Co-developed-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_driver.c   |  34 +----
 drivers/media/usb/uvc/uvc_metadata.c |   8 +-
 drivers/media/usb/uvc/uvc_queue.c    | 143 --------------------
 drivers/media/usb/uvc/uvc_v4l2.c     | 251 +++--------------------------------
 drivers/media/usb/uvc/uvcvideo.h     |  37 +-----
 5 files changed, 30 insertions(+), 443 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index da24a655ab68cc0957762f2b67387677c22224d1..4eeedab93b90939fc4c925012a18b7d018ade39f 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -1725,7 +1725,6 @@ static struct uvc_video_chain *uvc_alloc_chain(struct uvc_device *dev)
 	INIT_LIST_HEAD(&chain->entities);
 	mutex_init(&chain->ctrl_mutex);
 	chain->dev = dev;
-	v4l2_prio_init(&chain->prio);
 
 	return chain;
 }
@@ -1958,31 +1957,7 @@ static void uvc_unregister_video(struct uvc_device *dev)
 		if (!video_is_registered(&stream->vdev))
 			continue;
 
-		/*
-		 * For stream->vdev we follow the same logic as:
-		 * vb2_video_unregister_device().
-		 */
-
-		/* 1. Take a reference to vdev */
-		get_device(&stream->vdev.dev);
-
-		/* 2. Ensure that no new ioctls can be called. */
-		video_unregister_device(&stream->vdev);
-
-		/* 3. Wait for old ioctls to finish. */
-		mutex_lock(&stream->mutex);
-
-		/* 4. Stop streaming. */
-		uvc_queue_release(&stream->queue);
-
-		mutex_unlock(&stream->mutex);
-
-		put_device(&stream->vdev.dev);
-
-		/*
-		 * For stream->meta.vdev we can directly call:
-		 * vb2_video_unregister_device().
-		 */
+		vb2_video_unregister_device(&stream->vdev);
 		vb2_video_unregister_device(&stream->meta.vdev);
 
 		/*
@@ -2029,7 +2004,8 @@ int uvc_register_video_device(struct uvc_device *dev,
 	vdev->fops = fops;
 	vdev->ioctl_ops = ioctl_ops;
 	vdev->release = uvc_release;
-	vdev->prio = &stream->chain->prio;
+	vdev->queue = &queue->queue;
+	vdev->lock = &queue->mutex;
 	if (type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
 		vdev->vfl_dir = VFL_DIR_TX;
 	else
@@ -2399,8 +2375,8 @@ static int __uvc_resume(struct usb_interface *intf, int reset)
 		if (stream->intf == intf) {
 			ret = uvc_video_resume(stream, reset);
 			if (ret < 0)
-				uvc_queue_streamoff(&stream->queue,
-						    stream->queue.queue.type);
+				vb2_streamoff(&stream->queue.queue,
+					      stream->queue.queue.type);
 			return ret;
 		}
 	}
diff --git a/drivers/media/usb/uvc/uvc_metadata.c b/drivers/media/usb/uvc/uvc_metadata.c
index 82de7781f5b6b70c5ba16bcba9e0741231231904..d3aab22f91cea21aefc56409924dfa1451aec914 100644
--- a/drivers/media/usb/uvc/uvc_metadata.c
+++ b/drivers/media/usb/uvc/uvc_metadata.c
@@ -96,7 +96,7 @@ static int uvc_meta_v4l2_set_format(struct file *file, void *fh,
 	 */
 	mutex_lock(&stream->mutex);
 
-	if (uvc_queue_allocated(&stream->queue))
+	if (vb2_is_busy(&stream->meta.queue.queue))
 		ret = -EBUSY;
 	else
 		stream->meta.format = fmt->dataformat;
@@ -164,12 +164,6 @@ int uvc_meta_register(struct uvc_streaming *stream)
 
 	stream->meta.format = V4L2_META_FMT_UVC;
 
-	/*
-	 * The video interface queue uses manual locking and thus does not set
-	 * the queue pointer. Set it manually here.
-	 */
-	vdev->queue = &queue->queue;
-
 	return uvc_register_video_device(dev, stream, vdev, queue,
 					 V4L2_BUF_TYPE_META_CAPTURE,
 					 &uvc_meta_fops, &uvc_meta_ioctl_ops);
diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
index 2ee142621042167c2587b6a6fdd51c1a46d31c11..72c5494dee9f46ff61072e7d293bfaddda40e615 100644
--- a/drivers/media/usb/uvc/uvc_queue.c
+++ b/drivers/media/usb/uvc/uvc_queue.c
@@ -242,153 +242,10 @@ int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type)
 	return 0;
 }
 
-void uvc_queue_release(struct uvc_video_queue *queue)
-{
-	mutex_lock(&queue->mutex);
-	vb2_queue_release(&queue->queue);
-	mutex_unlock(&queue->mutex);
-}
-
-/* -----------------------------------------------------------------------------
- * V4L2 queue operations
- */
-
-int uvc_request_buffers(struct uvc_video_queue *queue,
-			struct v4l2_requestbuffers *rb)
-{
-	int ret;
-
-	mutex_lock(&queue->mutex);
-	ret = vb2_reqbufs(&queue->queue, rb);
-	mutex_unlock(&queue->mutex);
-
-	return ret ? ret : rb->count;
-}
-
-int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
-{
-	int ret;
-
-	mutex_lock(&queue->mutex);
-	ret = vb2_querybuf(&queue->queue, buf);
-	mutex_unlock(&queue->mutex);
-
-	return ret;
-}
-
-int uvc_create_buffers(struct uvc_video_queue *queue,
-		       struct v4l2_create_buffers *cb)
-{
-	int ret;
-
-	mutex_lock(&queue->mutex);
-	ret = vb2_create_bufs(&queue->queue, cb);
-	mutex_unlock(&queue->mutex);
-
-	return ret;
-}
-
-int uvc_queue_buffer(struct uvc_video_queue *queue,
-		     struct media_device *mdev, struct v4l2_buffer *buf)
-{
-	int ret;
-
-	mutex_lock(&queue->mutex);
-	ret = vb2_qbuf(&queue->queue, mdev, buf);
-	mutex_unlock(&queue->mutex);
-
-	return ret;
-}
-
-int uvc_export_buffer(struct uvc_video_queue *queue,
-		      struct v4l2_exportbuffer *exp)
-{
-	int ret;
-
-	mutex_lock(&queue->mutex);
-	ret = vb2_expbuf(&queue->queue, exp);
-	mutex_unlock(&queue->mutex);
-
-	return ret;
-}
-
-int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
-		       int nonblocking)
-{
-	int ret;
-
-	mutex_lock(&queue->mutex);
-	ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
-	mutex_unlock(&queue->mutex);
-
-	return ret;
-}
-
-int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type)
-{
-	int ret;
-
-	mutex_lock(&queue->mutex);
-	ret = vb2_streamon(&queue->queue, type);
-	mutex_unlock(&queue->mutex);
-
-	return ret;
-}
-
-int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type)
-{
-	int ret;
-
-	mutex_lock(&queue->mutex);
-	ret = vb2_streamoff(&queue->queue, type);
-	mutex_unlock(&queue->mutex);
-
-	return ret;
-}
-
-int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
-{
-	return vb2_mmap(&queue->queue, vma);
-}
-
-#ifndef CONFIG_MMU
-unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
-		unsigned long pgoff)
-{
-	return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
-}
-#endif
-
-__poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
-			    poll_table *wait)
-{
-	__poll_t ret;
-
-	mutex_lock(&queue->mutex);
-	ret = vb2_poll(&queue->queue, file, wait);
-	mutex_unlock(&queue->mutex);
-
-	return ret;
-}
-
 /* -----------------------------------------------------------------------------
  *
  */
 
-/*
- * Check if buffers have been allocated.
- */
-int uvc_queue_allocated(struct uvc_video_queue *queue)
-{
-	int allocated;
-
-	mutex_lock(&queue->mutex);
-	allocated = vb2_is_busy(&queue->queue);
-	mutex_unlock(&queue->mutex);
-
-	return allocated;
-}
-
 /*
  * Cancel the video buffers queue.
  *
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 862b4e34e5b629cf324479a9bb59ebe8784ccd5d..7a5ecbefa32c0a6b74c85d7f77a25b433598471e 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -47,8 +47,6 @@ void uvc_pm_put(struct uvc_device *dev)
 	usb_autopm_put_interface(dev->intf);
 }
 
-static int uvc_acquire_privileges(struct uvc_fh *handle);
-
 static int uvc_control_add_xu_mapping(struct uvc_video_chain *chain,
 				      struct uvc_control_mapping *map,
 				      const struct uvc_xu_control_mapping *xmap)
@@ -436,10 +434,6 @@ static int uvc_ioctl_s_fmt(struct file *file, void *fh,
 	const struct uvc_frame *frame;
 	int ret;
 
-	ret = uvc_acquire_privileges(handle);
-	if (ret < 0)
-		return ret;
-
 	if (fmt->type != stream->type)
 		return -EINVAL;
 
@@ -448,8 +442,7 @@ static int uvc_ioctl_s_fmt(struct file *file, void *fh,
 		return ret;
 
 	mutex_lock(&stream->mutex);
-
-	if (uvc_queue_allocated(&stream->queue)) {
+	if (vb2_is_busy(&stream->queue.queue)) {
 		ret = -EBUSY;
 		goto done;
 	}
@@ -513,10 +506,6 @@ static int uvc_ioctl_s_parm(struct file *file, void *fh,
 	unsigned int i;
 	int ret;
 
-	ret = uvc_acquire_privileges(handle);
-	if (ret < 0)
-		return ret;
-
 	if (parm->type != stream->type)
 		return -EINVAL;
 
@@ -593,63 +582,6 @@ static int uvc_ioctl_s_parm(struct file *file, void *fh,
 	return 0;
 }
 
-/* ------------------------------------------------------------------------
- * Privilege management
- */
-
-/*
- * Privilege management is the multiple-open implementation basis. The current
- * implementation is completely transparent for the end-user and doesn't
- * require explicit use of the VIDIOC_G_PRIORITY and VIDIOC_S_PRIORITY ioctls.
- * Those ioctls enable finer control on the device (by making possible for a
- * user to request exclusive access to a device), but are not mature yet.
- * Switching to the V4L2 priority mechanism might be considered in the future
- * if this situation changes.
- *
- * Each open instance of a UVC device can either be in a privileged or
- * unprivileged state. Only a single instance can be in a privileged state at
- * a given time. Trying to perform an operation that requires privileges will
- * automatically acquire the required privileges if possible, or return -EBUSY
- * otherwise. Privileges are dismissed when closing the instance or when
- * freeing the video buffers using VIDIOC_REQBUFS.
- *
- * Operations that require privileges are:
- *
- * - VIDIOC_S_INPUT
- * - VIDIOC_S_PARM
- * - VIDIOC_S_FMT
- * - VIDIOC_CREATE_BUFS
- * - VIDIOC_REQBUFS
- */
-static int uvc_acquire_privileges(struct uvc_fh *handle)
-{
-	/* Always succeed if the handle is already privileged. */
-	if (handle->state == UVC_HANDLE_ACTIVE)
-		return 0;
-
-	/* Check if the device already has a privileged handle. */
-	if (atomic_inc_return(&handle->stream->active) != 1) {
-		atomic_dec(&handle->stream->active);
-		return -EBUSY;
-	}
-
-	handle->state = UVC_HANDLE_ACTIVE;
-	return 0;
-}
-
-static void uvc_dismiss_privileges(struct uvc_fh *handle)
-{
-	if (handle->state == UVC_HANDLE_ACTIVE)
-		atomic_dec(&handle->stream->active);
-
-	handle->state = UVC_HANDLE_PASSIVE;
-}
-
-static int uvc_has_privileges(struct uvc_fh *handle)
-{
-	return handle->state == UVC_HANDLE_ACTIVE;
-}
-
 /* ------------------------------------------------------------------------
  * V4L2 file operations
  */
@@ -671,7 +603,6 @@ static int uvc_v4l2_open(struct file *file)
 	v4l2_fh_add(&handle->vfh);
 	handle->chain = stream->chain;
 	handle->stream = stream;
-	handle->state = UVC_HANDLE_PASSIVE;
 	file->private_data = handle;
 
 	return 0;
@@ -686,18 +617,11 @@ static int uvc_v4l2_release(struct file *file)
 
 	uvc_ctrl_cleanup_fh(handle);
 
-	/* Only free resources if this is a privileged handle. */
-	if (uvc_has_privileges(handle))
-		uvc_queue_release(&stream->queue);
-
 	if (handle->is_streaming)
 		uvc_pm_put(stream->dev);
 
 	/* Release the file handle. */
-	uvc_dismiss_privileges(handle);
-	v4l2_fh_del(&handle->vfh);
-	v4l2_fh_exit(&handle->vfh);
-	kfree(handle);
+	vb2_fop_release(file);
 	file->private_data = NULL;
 
 	return 0;
@@ -753,91 +677,6 @@ static int uvc_ioctl_try_fmt(struct file *file, void *fh,
 	return uvc_v4l2_try_format(stream, fmt, &probe, NULL, NULL);
 }
 
-static int uvc_ioctl_reqbufs(struct file *file, void *fh,
-			     struct v4l2_requestbuffers *rb)
-{
-	struct uvc_fh *handle = fh;
-	struct uvc_streaming *stream = handle->stream;
-	int ret;
-
-	ret = uvc_acquire_privileges(handle);
-	if (ret < 0)
-		return ret;
-
-	mutex_lock(&stream->mutex);
-	ret = uvc_request_buffers(&stream->queue, rb);
-	mutex_unlock(&stream->mutex);
-	if (ret < 0)
-		return ret;
-
-	if (ret == 0)
-		uvc_dismiss_privileges(handle);
-
-	return 0;
-}
-
-static int uvc_ioctl_querybuf(struct file *file, void *fh,
-			      struct v4l2_buffer *buf)
-{
-	struct uvc_fh *handle = fh;
-	struct uvc_streaming *stream = handle->stream;
-
-	if (!uvc_has_privileges(handle))
-		return -EBUSY;
-
-	return uvc_query_buffer(&stream->queue, buf);
-}
-
-static int uvc_ioctl_qbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
-{
-	struct uvc_fh *handle = fh;
-	struct uvc_streaming *stream = handle->stream;
-
-	if (!uvc_has_privileges(handle))
-		return -EBUSY;
-
-	return uvc_queue_buffer(&stream->queue,
-				stream->vdev.v4l2_dev->mdev, buf);
-}
-
-static int uvc_ioctl_expbuf(struct file *file, void *fh,
-			    struct v4l2_exportbuffer *exp)
-{
-	struct uvc_fh *handle = fh;
-	struct uvc_streaming *stream = handle->stream;
-
-	if (!uvc_has_privileges(handle))
-		return -EBUSY;
-
-	return uvc_export_buffer(&stream->queue, exp);
-}
-
-static int uvc_ioctl_dqbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
-{
-	struct uvc_fh *handle = fh;
-	struct uvc_streaming *stream = handle->stream;
-
-	if (!uvc_has_privileges(handle))
-		return -EBUSY;
-
-	return uvc_dequeue_buffer(&stream->queue, buf,
-				  file->f_flags & O_NONBLOCK);
-}
-
-static int uvc_ioctl_create_bufs(struct file *file, void *fh,
-				  struct v4l2_create_buffers *cb)
-{
-	struct uvc_fh *handle = fh;
-	struct uvc_streaming *stream = handle->stream;
-	int ret;
-
-	ret = uvc_acquire_privileges(handle);
-	if (ret < 0)
-		return ret;
-
-	return uvc_create_buffers(&stream->queue, cb);
-}
-
 static int uvc_ioctl_streamon(struct file *file, void *fh,
 			      enum v4l2_buf_type type)
 {
@@ -845,11 +684,6 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
 	struct uvc_streaming *stream = handle->stream;
 	int ret;
 
-	if (!uvc_has_privileges(handle))
-		return -EBUSY;
-
-	guard(mutex)(&stream->mutex);
-
 	if (handle->is_streaming)
 		return 0;
 
@@ -857,7 +691,7 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
 	if (ret)
 		return ret;
 
-	ret = uvc_queue_streamon(&stream->queue, type);
+	ret = vb2_ioctl_streamon(file, fh, type);
 	if (ret) {
 		uvc_pm_put(stream->dev);
 		return ret;
@@ -873,13 +707,12 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
 {
 	struct uvc_fh *handle = fh;
 	struct uvc_streaming *stream = handle->stream;
+	int ret;
 
-	if (!uvc_has_privileges(handle))
-		return -EBUSY;
-
-	guard(mutex)(&stream->mutex);
+	ret = vb2_ioctl_streamoff(file, fh, type);
+	if (ret)
+		return ret;
 
-	uvc_queue_streamoff(&stream->queue, type);
 	if (handle->is_streaming) {
 		handle->is_streaming = false;
 		uvc_pm_put(stream->dev);
@@ -962,13 +795,13 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
 static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
 {
 	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
 	struct uvc_video_chain *chain = handle->chain;
 	u8 *buf;
 	int ret;
 
-	ret = uvc_acquire_privileges(handle);
-	if (ret < 0)
-		return ret;
+	if (vb2_is_busy(&stream->queue.queue))
+		return -EBUSY;
 
 	if (chain->selector == NULL ||
 	    (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
@@ -1471,50 +1304,6 @@ static long uvc_v4l2_unlocked_ioctl(struct file *file,
 	return ret;
 }
 
-static ssize_t uvc_v4l2_read(struct file *file, char __user *data,
-		    size_t count, loff_t *ppos)
-{
-	struct uvc_fh *handle = file->private_data;
-	struct uvc_streaming *stream = handle->stream;
-
-	uvc_dbg(stream->dev, CALLS, "%s: not implemented\n", __func__);
-	return -EINVAL;
-}
-
-static int uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
-{
-	struct uvc_fh *handle = file->private_data;
-	struct uvc_streaming *stream = handle->stream;
-
-	uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
-
-	return uvc_queue_mmap(&stream->queue, vma);
-}
-
-static __poll_t uvc_v4l2_poll(struct file *file, poll_table *wait)
-{
-	struct uvc_fh *handle = file->private_data;
-	struct uvc_streaming *stream = handle->stream;
-
-	uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
-
-	return uvc_queue_poll(&stream->queue, file, wait);
-}
-
-#ifndef CONFIG_MMU
-static unsigned long uvc_v4l2_get_unmapped_area(struct file *file,
-		unsigned long addr, unsigned long len, unsigned long pgoff,
-		unsigned long flags)
-{
-	struct uvc_fh *handle = file->private_data;
-	struct uvc_streaming *stream = handle->stream;
-
-	uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
-
-	return uvc_queue_get_unmapped_area(&stream->queue, pgoff);
-}
-#endif
-
 const struct v4l2_ioctl_ops uvc_ioctl_ops = {
 	.vidioc_g_fmt_vid_cap = uvc_ioctl_g_fmt,
 	.vidioc_g_fmt_vid_out = uvc_ioctl_g_fmt,
@@ -1527,12 +1316,13 @@ const struct v4l2_ioctl_ops uvc_ioctl_ops = {
 	.vidioc_enum_fmt_vid_out = uvc_ioctl_enum_fmt,
 	.vidioc_try_fmt_vid_cap = uvc_ioctl_try_fmt,
 	.vidioc_try_fmt_vid_out = uvc_ioctl_try_fmt,
-	.vidioc_reqbufs = uvc_ioctl_reqbufs,
-	.vidioc_querybuf = uvc_ioctl_querybuf,
-	.vidioc_qbuf = uvc_ioctl_qbuf,
-	.vidioc_expbuf = uvc_ioctl_expbuf,
-	.vidioc_dqbuf = uvc_ioctl_dqbuf,
-	.vidioc_create_bufs = uvc_ioctl_create_bufs,
+	.vidioc_reqbufs = vb2_ioctl_reqbufs,
+	.vidioc_querybuf = vb2_ioctl_querybuf,
+	.vidioc_prepare_buf = vb2_ioctl_prepare_buf,
+	.vidioc_qbuf = vb2_ioctl_qbuf,
+	.vidioc_expbuf = vb2_ioctl_expbuf,
+	.vidioc_dqbuf = vb2_ioctl_dqbuf,
+	.vidioc_create_bufs = vb2_ioctl_create_bufs,
 	.vidioc_streamon = uvc_ioctl_streamon,
 	.vidioc_streamoff = uvc_ioctl_streamoff,
 	.vidioc_enum_input = uvc_ioctl_enum_input,
@@ -1559,11 +1349,10 @@ const struct v4l2_file_operations uvc_fops = {
 #ifdef CONFIG_COMPAT
 	.compat_ioctl32	= uvc_v4l2_compat_ioctl32,
 #endif
-	.read		= uvc_v4l2_read,
-	.mmap		= uvc_v4l2_mmap,
-	.poll		= uvc_v4l2_poll,
+	.mmap		= vb2_fop_mmap,
+	.poll		= vb2_fop_poll,
 #ifndef CONFIG_MMU
-	.get_unmapped_area = uvc_v4l2_get_unmapped_area,
+	.get_unmapped_area = vb2_fop_get_unmapped_area,
 #endif
 };
 
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index b9f8eb62ba1d82ea7788cf6c10cc838a429dbc9e..3ddbf065a2cbae40ee48cb06f84ca8f0052990c4 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -326,7 +326,10 @@ struct uvc_buffer {
 
 struct uvc_video_queue {
 	struct vb2_queue queue;
-	struct mutex mutex;			/* Protects queue */
+	struct mutex mutex;			/*
+						 * Serializes vb2_queue and
+						 * fops
+						 */
 
 	unsigned int flags;
 	unsigned int buf_used;
@@ -349,7 +352,6 @@ struct uvc_video_chain {
 						 * uvc_fh.pending_async_ctrls
 						 */
 
-	struct v4l2_prio_state prio;		/* V4L2 priority state */
 	u32 caps;				/* V4L2 chain-wide caps */
 	u8 ctrl_class_bitmap;			/* Bitmap of valid classes */
 };
@@ -619,16 +621,10 @@ struct uvc_device {
 	struct uvc_entity *gpio_unit;
 };
 
-enum uvc_handle_state {
-	UVC_HANDLE_PASSIVE	= 0,
-	UVC_HANDLE_ACTIVE	= 1,
-};
-
 struct uvc_fh {
 	struct v4l2_fh vfh;
 	struct uvc_video_chain *chain;
 	struct uvc_streaming *stream;
-	enum uvc_handle_state state;
 	unsigned int pending_async_ctrls;
 	bool is_streaming;
 };
@@ -687,36 +683,11 @@ struct uvc_entity *uvc_entity_by_id(struct uvc_device *dev, int id);
 
 /* Video buffers queue management. */
 int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type);
-void uvc_queue_release(struct uvc_video_queue *queue);
-int uvc_request_buffers(struct uvc_video_queue *queue,
-			struct v4l2_requestbuffers *rb);
-int uvc_query_buffer(struct uvc_video_queue *queue,
-		     struct v4l2_buffer *v4l2_buf);
-int uvc_create_buffers(struct uvc_video_queue *queue,
-		       struct v4l2_create_buffers *v4l2_cb);
-int uvc_queue_buffer(struct uvc_video_queue *queue,
-		     struct media_device *mdev,
-		     struct v4l2_buffer *v4l2_buf);
-int uvc_export_buffer(struct uvc_video_queue *queue,
-		      struct v4l2_exportbuffer *exp);
-int uvc_dequeue_buffer(struct uvc_video_queue *queue,
-		       struct v4l2_buffer *v4l2_buf, int nonblocking);
-int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type);
-int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type);
 void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect);
 struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
 					 struct uvc_buffer *buf);
 struct uvc_buffer *uvc_queue_get_current_buffer(struct uvc_video_queue *queue);
 void uvc_queue_buffer_release(struct uvc_buffer *buf);
-int uvc_queue_mmap(struct uvc_video_queue *queue,
-		   struct vm_area_struct *vma);
-__poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
-			poll_table *wait);
-#ifndef CONFIG_MMU
-unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
-					  unsigned long pgoff);
-#endif
-int uvc_queue_allocated(struct uvc_video_queue *queue);
 static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
 {
 	return vb2_is_streaming(&queue->queue);

-- 
2.49.0.1151.ga128411c76-goog

[PATCH 3/3] media: uvcvideo: Remove stream->is_streaming field

[Ricardo Ribalda]

The is_streaming field is used by modular PM to know if the device is
currently streaming or not.

With the transition to vb2 and fop helpers, we can use vb2 functions for
the same functionality.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_v4l2.c | 12 +++++-------
 drivers/media/usb/uvc/uvcvideo.h |  1 -
 2 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 7a5ecbefa32c0a6b74c85d7f77a25b433598471e..51419f443f2c43dfd17a9782352bd2cde1094732 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -617,7 +617,8 @@ static int uvc_v4l2_release(struct file *file)
 
 	uvc_ctrl_cleanup_fh(handle);
 
-	if (handle->is_streaming)
+	if (stream->queue.queue.owner == file->private_data &&
+	    uvc_queue_streaming(&stream->queue))
 		uvc_pm_put(stream->dev);
 
 	/* Release the file handle. */
@@ -684,7 +685,7 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
 	struct uvc_streaming *stream = handle->stream;
 	int ret;
 
-	if (handle->is_streaming)
+	if (uvc_queue_streaming(&stream->queue))
 		return 0;
 
 	ret = uvc_pm_get(stream->dev);
@@ -697,8 +698,6 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
 		return ret;
 	}
 
-	handle->is_streaming = true;
-
 	return 0;
 }
 
@@ -707,16 +706,15 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
 {
 	struct uvc_fh *handle = fh;
 	struct uvc_streaming *stream = handle->stream;
+	bool was_streaming = uvc_queue_streaming(&stream->queue);
 	int ret;
 
 	ret = vb2_ioctl_streamoff(file, fh, type);
 	if (ret)
 		return ret;
 
-	if (handle->is_streaming) {
-		handle->is_streaming = false;
+	if (was_streaming)
 		uvc_pm_put(stream->dev);
-	}
 
 	return 0;
 }
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 3ddbf065a2cbae40ee48cb06f84ca8f0052990c4..f895f690f7cdc1af942d5f3a5f10e9dd1c956a35 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -626,7 +626,6 @@ struct uvc_fh {
 	struct uvc_video_chain *chain;
 	struct uvc_streaming *stream;
 	unsigned int pending_async_ctrls;
-	bool is_streaming;
 };
 
 /* ------------------------------------------------------------------------

-- 
2.49.0.1151.ga128411c76-goog

Re: [PATCH 1/3] media: uvcvideo: Refactor uvc_queue_streamon

[Laurent Pinchart]

Hi Ricardo,

Thank you for the patch.

On Thu, May 22, 2025 at 05:58:46PM +0000, Ricardo Ribalda wrote:
> Do uvc_pm_get before we call uvc_queue_streamon. Although the current
> code is correct, uvc_ioctl_streamon is allways called after uvc_pm_get,
> this change makes the code more resiliant to future changes.
> 
> Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
>  drivers/media/usb/uvc/uvc_v4l2.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> index 668a4e9d772c6d91f045ca75e2744b3a6c69da6b..862b4e34e5b629cf324479a9bb59ebe8784ccd5d 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -853,15 +853,16 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
>  	if (handle->is_streaming)
>  		return 0;
>  
> -	ret = uvc_queue_streamon(&stream->queue, type);
> +	ret = uvc_pm_get(stream->dev);
>  	if (ret)
>  		return ret;
>  
> -	ret = uvc_pm_get(stream->dev);
> +	ret = uvc_queue_streamon(&stream->queue, type);
>  	if (ret) {
> -		uvc_queue_streamoff(&stream->queue, type);
> +		uvc_pm_put(stream->dev);
>  		return ret;
>  	}
> +
>  	handle->is_streaming = true;
>  
>  	return 0;

-- 
Regards,

Laurent Pinchart

Re: [PATCH 1/3] media: uvcvideo: Refactor uvc_queue_streamon

[Ricardo Ribalda]

Hi Laurent

Thanks for your review

On Thu, 22 May 2025 at 23:40, Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>
> Hi Ricardo,
>
> Thank you for the patch.
>
> On Thu, May 22, 2025 at 05:58:46PM +0000, Ricardo Ribalda wrote:
> > Do uvc_pm_get before we call uvc_queue_streamon. Although the current
> > code is correct, uvc_ioctl_streamon is allways called after uvc_pm_get,
> > this change makes the code more resiliant to future changes.
> >
> > Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Unless you say otherwise I will copy this Review-by to the original
series where this patch belongs to.
https://patchwork.linuxtv.org/project/linux-media/list/?series=15227

Thanks!


>
> > ---
> >  drivers/media/usb/uvc/uvc_v4l2.c | 7 ++++---
> >  1 file changed, 4 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> > index 668a4e9d772c6d91f045ca75e2744b3a6c69da6b..862b4e34e5b629cf324479a9bb59ebe8784ccd5d 100644
> > --- a/drivers/media/usb/uvc/uvc_v4l2.c
> > +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> > @@ -853,15 +853,16 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
> >       if (handle->is_streaming)
> >               return 0;
> >
> > -     ret = uvc_queue_streamon(&stream->queue, type);
> > +     ret = uvc_pm_get(stream->dev);
> >       if (ret)
> >               return ret;
> >
> > -     ret = uvc_pm_get(stream->dev);
> > +     ret = uvc_queue_streamon(&stream->queue, type);
> >       if (ret) {
> > -             uvc_queue_streamoff(&stream->queue, type);
> > +             uvc_pm_put(stream->dev);
> >               return ret;
> >       }
> > +
> >       handle->is_streaming = true;
> >
> >       return 0;
>
> --
> Regards,
>
> Laurent Pinchart



-- 
Ricardo Ribalda

Re: [PATCH 2/3] media: uvcvideo: Use vb2 ioctl and fop helpers

[Hans de Goede]

Hi,

On 22-May-25 19:58, Ricardo Ribalda wrote:
> From: Hans Verkuil <hans@jjverkuil.nl>
> 
> When uvc was written the vb2 ioctl and file operation helpers didn't exist.
> 
> This patch switches uvc over to those helpers, which removes a lot of
> boilerplatecode and simplifies VIDIOC_G/S_PRIORITY handling and allows us
> to drop the 'privileges' scheme, since that's now handled inside the vb2
> helpers.
> 
> This makes it possible for uvc to fix the v4l2-compliance streaming tests:
>  warn: v4l2-test-formats.cpp(1075): Could not set fmt2
> 
> This patch introduces a change on behavior on the uvcdriver to be
> aligned with the rest of the subsystem. Now S_INPUT, S_PARM and
> S_FORMAT do no gran exclusive ownership of the device.
> 
> Signed-off-by: Hans Verkuil <hans@jjverkuil.nl>
> Co-developed-by: Ricardo Ribalda <ribalda@chromium.org>
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <hansg@kernel.org>

Regards,

Hans

> ---
>  drivers/media/usb/uvc/uvc_driver.c   |  34 +----
>  drivers/media/usb/uvc/uvc_metadata.c |   8 +-
>  drivers/media/usb/uvc/uvc_queue.c    | 143 --------------------
>  drivers/media/usb/uvc/uvc_v4l2.c     | 251 +++--------------------------------
>  drivers/media/usb/uvc/uvcvideo.h     |  37 +-----
>  5 files changed, 30 insertions(+), 443 deletions(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> index da24a655ab68cc0957762f2b67387677c22224d1..4eeedab93b90939fc4c925012a18b7d018ade39f 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -1725,7 +1725,6 @@ static struct uvc_video_chain *uvc_alloc_chain(struct uvc_device *dev)
>  	INIT_LIST_HEAD(&chain->entities);
>  	mutex_init(&chain->ctrl_mutex);
>  	chain->dev = dev;
> -	v4l2_prio_init(&chain->prio);
>  
>  	return chain;
>  }
> @@ -1958,31 +1957,7 @@ static void uvc_unregister_video(struct uvc_device *dev)
>  		if (!video_is_registered(&stream->vdev))
>  			continue;
>  
> -		/*
> -		 * For stream->vdev we follow the same logic as:
> -		 * vb2_video_unregister_device().
> -		 */
> -
> -		/* 1. Take a reference to vdev */
> -		get_device(&stream->vdev.dev);
> -
> -		/* 2. Ensure that no new ioctls can be called. */
> -		video_unregister_device(&stream->vdev);
> -
> -		/* 3. Wait for old ioctls to finish. */
> -		mutex_lock(&stream->mutex);
> -
> -		/* 4. Stop streaming. */
> -		uvc_queue_release(&stream->queue);
> -
> -		mutex_unlock(&stream->mutex);
> -
> -		put_device(&stream->vdev.dev);
> -
> -		/*
> -		 * For stream->meta.vdev we can directly call:
> -		 * vb2_video_unregister_device().
> -		 */
> +		vb2_video_unregister_device(&stream->vdev);
>  		vb2_video_unregister_device(&stream->meta.vdev);
>  
>  		/*
> @@ -2029,7 +2004,8 @@ int uvc_register_video_device(struct uvc_device *dev,
>  	vdev->fops = fops;
>  	vdev->ioctl_ops = ioctl_ops;
>  	vdev->release = uvc_release;
> -	vdev->prio = &stream->chain->prio;
> +	vdev->queue = &queue->queue;
> +	vdev->lock = &queue->mutex;
>  	if (type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
>  		vdev->vfl_dir = VFL_DIR_TX;
>  	else
> @@ -2399,8 +2375,8 @@ static int __uvc_resume(struct usb_interface *intf, int reset)
>  		if (stream->intf == intf) {
>  			ret = uvc_video_resume(stream, reset);
>  			if (ret < 0)
> -				uvc_queue_streamoff(&stream->queue,
> -						    stream->queue.queue.type);
> +				vb2_streamoff(&stream->queue.queue,
> +					      stream->queue.queue.type);
>  			return ret;
>  		}
>  	}
> diff --git a/drivers/media/usb/uvc/uvc_metadata.c b/drivers/media/usb/uvc/uvc_metadata.c
> index 82de7781f5b6b70c5ba16bcba9e0741231231904..d3aab22f91cea21aefc56409924dfa1451aec914 100644
> --- a/drivers/media/usb/uvc/uvc_metadata.c
> +++ b/drivers/media/usb/uvc/uvc_metadata.c
> @@ -96,7 +96,7 @@ static int uvc_meta_v4l2_set_format(struct file *file, void *fh,
>  	 */
>  	mutex_lock(&stream->mutex);
>  
> -	if (uvc_queue_allocated(&stream->queue))
> +	if (vb2_is_busy(&stream->meta.queue.queue))
>  		ret = -EBUSY;
>  	else
>  		stream->meta.format = fmt->dataformat;
> @@ -164,12 +164,6 @@ int uvc_meta_register(struct uvc_streaming *stream)
>  
>  	stream->meta.format = V4L2_META_FMT_UVC;
>  
> -	/*
> -	 * The video interface queue uses manual locking and thus does not set
> -	 * the queue pointer. Set it manually here.
> -	 */
> -	vdev->queue = &queue->queue;
> -
>  	return uvc_register_video_device(dev, stream, vdev, queue,
>  					 V4L2_BUF_TYPE_META_CAPTURE,
>  					 &uvc_meta_fops, &uvc_meta_ioctl_ops);
> diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
> index 2ee142621042167c2587b6a6fdd51c1a46d31c11..72c5494dee9f46ff61072e7d293bfaddda40e615 100644
> --- a/drivers/media/usb/uvc/uvc_queue.c
> +++ b/drivers/media/usb/uvc/uvc_queue.c
> @@ -242,153 +242,10 @@ int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type)
>  	return 0;
>  }
>  
> -void uvc_queue_release(struct uvc_video_queue *queue)
> -{
> -	mutex_lock(&queue->mutex);
> -	vb2_queue_release(&queue->queue);
> -	mutex_unlock(&queue->mutex);
> -}
> -
> -/* -----------------------------------------------------------------------------
> - * V4L2 queue operations
> - */
> -
> -int uvc_request_buffers(struct uvc_video_queue *queue,
> -			struct v4l2_requestbuffers *rb)
> -{
> -	int ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_reqbufs(&queue->queue, rb);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret ? ret : rb->count;
> -}
> -
> -int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
> -{
> -	int ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_querybuf(&queue->queue, buf);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret;
> -}
> -
> -int uvc_create_buffers(struct uvc_video_queue *queue,
> -		       struct v4l2_create_buffers *cb)
> -{
> -	int ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_create_bufs(&queue->queue, cb);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret;
> -}
> -
> -int uvc_queue_buffer(struct uvc_video_queue *queue,
> -		     struct media_device *mdev, struct v4l2_buffer *buf)
> -{
> -	int ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_qbuf(&queue->queue, mdev, buf);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret;
> -}
> -
> -int uvc_export_buffer(struct uvc_video_queue *queue,
> -		      struct v4l2_exportbuffer *exp)
> -{
> -	int ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_expbuf(&queue->queue, exp);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret;
> -}
> -
> -int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
> -		       int nonblocking)
> -{
> -	int ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret;
> -}
> -
> -int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type)
> -{
> -	int ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_streamon(&queue->queue, type);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret;
> -}
> -
> -int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type)
> -{
> -	int ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_streamoff(&queue->queue, type);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret;
> -}
> -
> -int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
> -{
> -	return vb2_mmap(&queue->queue, vma);
> -}
> -
> -#ifndef CONFIG_MMU
> -unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
> -		unsigned long pgoff)
> -{
> -	return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
> -}
> -#endif
> -
> -__poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
> -			    poll_table *wait)
> -{
> -	__poll_t ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_poll(&queue->queue, file, wait);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret;
> -}
> -
>  /* -----------------------------------------------------------------------------
>   *
>   */
>  
> -/*
> - * Check if buffers have been allocated.
> - */
> -int uvc_queue_allocated(struct uvc_video_queue *queue)
> -{
> -	int allocated;
> -
> -	mutex_lock(&queue->mutex);
> -	allocated = vb2_is_busy(&queue->queue);
> -	mutex_unlock(&queue->mutex);
> -
> -	return allocated;
> -}
> -
>  /*
>   * Cancel the video buffers queue.
>   *
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> index 862b4e34e5b629cf324479a9bb59ebe8784ccd5d..7a5ecbefa32c0a6b74c85d7f77a25b433598471e 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -47,8 +47,6 @@ void uvc_pm_put(struct uvc_device *dev)
>  	usb_autopm_put_interface(dev->intf);
>  }
>  
> -static int uvc_acquire_privileges(struct uvc_fh *handle);
> -
>  static int uvc_control_add_xu_mapping(struct uvc_video_chain *chain,
>  				      struct uvc_control_mapping *map,
>  				      const struct uvc_xu_control_mapping *xmap)
> @@ -436,10 +434,6 @@ static int uvc_ioctl_s_fmt(struct file *file, void *fh,
>  	const struct uvc_frame *frame;
>  	int ret;
>  
> -	ret = uvc_acquire_privileges(handle);
> -	if (ret < 0)
> -		return ret;
> -
>  	if (fmt->type != stream->type)
>  		return -EINVAL;
>  
> @@ -448,8 +442,7 @@ static int uvc_ioctl_s_fmt(struct file *file, void *fh,
>  		return ret;
>  
>  	mutex_lock(&stream->mutex);
> -
> -	if (uvc_queue_allocated(&stream->queue)) {
> +	if (vb2_is_busy(&stream->queue.queue)) {
>  		ret = -EBUSY;
>  		goto done;
>  	}
> @@ -513,10 +506,6 @@ static int uvc_ioctl_s_parm(struct file *file, void *fh,
>  	unsigned int i;
>  	int ret;
>  
> -	ret = uvc_acquire_privileges(handle);
> -	if (ret < 0)
> -		return ret;
> -
>  	if (parm->type != stream->type)
>  		return -EINVAL;
>  
> @@ -593,63 +582,6 @@ static int uvc_ioctl_s_parm(struct file *file, void *fh,
>  	return 0;
>  }
>  
> -/* ------------------------------------------------------------------------
> - * Privilege management
> - */
> -
> -/*
> - * Privilege management is the multiple-open implementation basis. The current
> - * implementation is completely transparent for the end-user and doesn't
> - * require explicit use of the VIDIOC_G_PRIORITY and VIDIOC_S_PRIORITY ioctls.
> - * Those ioctls enable finer control on the device (by making possible for a
> - * user to request exclusive access to a device), but are not mature yet.
> - * Switching to the V4L2 priority mechanism might be considered in the future
> - * if this situation changes.
> - *
> - * Each open instance of a UVC device can either be in a privileged or
> - * unprivileged state. Only a single instance can be in a privileged state at
> - * a given time. Trying to perform an operation that requires privileges will
> - * automatically acquire the required privileges if possible, or return -EBUSY
> - * otherwise. Privileges are dismissed when closing the instance or when
> - * freeing the video buffers using VIDIOC_REQBUFS.
> - *
> - * Operations that require privileges are:
> - *
> - * - VIDIOC_S_INPUT
> - * - VIDIOC_S_PARM
> - * - VIDIOC_S_FMT
> - * - VIDIOC_CREATE_BUFS
> - * - VIDIOC_REQBUFS
> - */
> -static int uvc_acquire_privileges(struct uvc_fh *handle)
> -{
> -	/* Always succeed if the handle is already privileged. */
> -	if (handle->state == UVC_HANDLE_ACTIVE)
> -		return 0;
> -
> -	/* Check if the device already has a privileged handle. */
> -	if (atomic_inc_return(&handle->stream->active) != 1) {
> -		atomic_dec(&handle->stream->active);
> -		return -EBUSY;
> -	}
> -
> -	handle->state = UVC_HANDLE_ACTIVE;
> -	return 0;
> -}
> -
> -static void uvc_dismiss_privileges(struct uvc_fh *handle)
> -{
> -	if (handle->state == UVC_HANDLE_ACTIVE)
> -		atomic_dec(&handle->stream->active);
> -
> -	handle->state = UVC_HANDLE_PASSIVE;
> -}
> -
> -static int uvc_has_privileges(struct uvc_fh *handle)
> -{
> -	return handle->state == UVC_HANDLE_ACTIVE;
> -}
> -
>  /* ------------------------------------------------------------------------
>   * V4L2 file operations
>   */
> @@ -671,7 +603,6 @@ static int uvc_v4l2_open(struct file *file)
>  	v4l2_fh_add(&handle->vfh);
>  	handle->chain = stream->chain;
>  	handle->stream = stream;
> -	handle->state = UVC_HANDLE_PASSIVE;
>  	file->private_data = handle;
>  
>  	return 0;
> @@ -686,18 +617,11 @@ static int uvc_v4l2_release(struct file *file)
>  
>  	uvc_ctrl_cleanup_fh(handle);
>  
> -	/* Only free resources if this is a privileged handle. */
> -	if (uvc_has_privileges(handle))
> -		uvc_queue_release(&stream->queue);
> -
>  	if (handle->is_streaming)
>  		uvc_pm_put(stream->dev);
>  
>  	/* Release the file handle. */
> -	uvc_dismiss_privileges(handle);
> -	v4l2_fh_del(&handle->vfh);
> -	v4l2_fh_exit(&handle->vfh);
> -	kfree(handle);
> +	vb2_fop_release(file);
>  	file->private_data = NULL;
>  
>  	return 0;
> @@ -753,91 +677,6 @@ static int uvc_ioctl_try_fmt(struct file *file, void *fh,
>  	return uvc_v4l2_try_format(stream, fmt, &probe, NULL, NULL);
>  }
>  
> -static int uvc_ioctl_reqbufs(struct file *file, void *fh,
> -			     struct v4l2_requestbuffers *rb)
> -{
> -	struct uvc_fh *handle = fh;
> -	struct uvc_streaming *stream = handle->stream;
> -	int ret;
> -
> -	ret = uvc_acquire_privileges(handle);
> -	if (ret < 0)
> -		return ret;
> -
> -	mutex_lock(&stream->mutex);
> -	ret = uvc_request_buffers(&stream->queue, rb);
> -	mutex_unlock(&stream->mutex);
> -	if (ret < 0)
> -		return ret;
> -
> -	if (ret == 0)
> -		uvc_dismiss_privileges(handle);
> -
> -	return 0;
> -}
> -
> -static int uvc_ioctl_querybuf(struct file *file, void *fh,
> -			      struct v4l2_buffer *buf)
> -{
> -	struct uvc_fh *handle = fh;
> -	struct uvc_streaming *stream = handle->stream;
> -
> -	if (!uvc_has_privileges(handle))
> -		return -EBUSY;
> -
> -	return uvc_query_buffer(&stream->queue, buf);
> -}
> -
> -static int uvc_ioctl_qbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
> -{
> -	struct uvc_fh *handle = fh;
> -	struct uvc_streaming *stream = handle->stream;
> -
> -	if (!uvc_has_privileges(handle))
> -		return -EBUSY;
> -
> -	return uvc_queue_buffer(&stream->queue,
> -				stream->vdev.v4l2_dev->mdev, buf);
> -}
> -
> -static int uvc_ioctl_expbuf(struct file *file, void *fh,
> -			    struct v4l2_exportbuffer *exp)
> -{
> -	struct uvc_fh *handle = fh;
> -	struct uvc_streaming *stream = handle->stream;
> -
> -	if (!uvc_has_privileges(handle))
> -		return -EBUSY;
> -
> -	return uvc_export_buffer(&stream->queue, exp);
> -}
> -
> -static int uvc_ioctl_dqbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
> -{
> -	struct uvc_fh *handle = fh;
> -	struct uvc_streaming *stream = handle->stream;
> -
> -	if (!uvc_has_privileges(handle))
> -		return -EBUSY;
> -
> -	return uvc_dequeue_buffer(&stream->queue, buf,
> -				  file->f_flags & O_NONBLOCK);
> -}
> -
> -static int uvc_ioctl_create_bufs(struct file *file, void *fh,
> -				  struct v4l2_create_buffers *cb)
> -{
> -	struct uvc_fh *handle = fh;
> -	struct uvc_streaming *stream = handle->stream;
> -	int ret;
> -
> -	ret = uvc_acquire_privileges(handle);
> -	if (ret < 0)
> -		return ret;
> -
> -	return uvc_create_buffers(&stream->queue, cb);
> -}
> -
>  static int uvc_ioctl_streamon(struct file *file, void *fh,
>  			      enum v4l2_buf_type type)
>  {
> @@ -845,11 +684,6 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
>  	struct uvc_streaming *stream = handle->stream;
>  	int ret;
>  
> -	if (!uvc_has_privileges(handle))
> -		return -EBUSY;
> -
> -	guard(mutex)(&stream->mutex);
> -
>  	if (handle->is_streaming)
>  		return 0;
>  
> @@ -857,7 +691,7 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
>  	if (ret)
>  		return ret;
>  
> -	ret = uvc_queue_streamon(&stream->queue, type);
> +	ret = vb2_ioctl_streamon(file, fh, type);
>  	if (ret) {
>  		uvc_pm_put(stream->dev);
>  		return ret;
> @@ -873,13 +707,12 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
>  {
>  	struct uvc_fh *handle = fh;
>  	struct uvc_streaming *stream = handle->stream;
> +	int ret;
>  
> -	if (!uvc_has_privileges(handle))
> -		return -EBUSY;
> -
> -	guard(mutex)(&stream->mutex);
> +	ret = vb2_ioctl_streamoff(file, fh, type);
> +	if (ret)
> +		return ret;
>  
> -	uvc_queue_streamoff(&stream->queue, type);
>  	if (handle->is_streaming) {
>  		handle->is_streaming = false;
>  		uvc_pm_put(stream->dev);
> @@ -962,13 +795,13 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
>  static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
>  {
>  	struct uvc_fh *handle = fh;
> +	struct uvc_streaming *stream = handle->stream;
>  	struct uvc_video_chain *chain = handle->chain;
>  	u8 *buf;
>  	int ret;
>  
> -	ret = uvc_acquire_privileges(handle);
> -	if (ret < 0)
> -		return ret;
> +	if (vb2_is_busy(&stream->queue.queue))
> +		return -EBUSY;
>  
>  	if (chain->selector == NULL ||
>  	    (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
> @@ -1471,50 +1304,6 @@ static long uvc_v4l2_unlocked_ioctl(struct file *file,
>  	return ret;
>  }
>  
> -static ssize_t uvc_v4l2_read(struct file *file, char __user *data,
> -		    size_t count, loff_t *ppos)
> -{
> -	struct uvc_fh *handle = file->private_data;
> -	struct uvc_streaming *stream = handle->stream;
> -
> -	uvc_dbg(stream->dev, CALLS, "%s: not implemented\n", __func__);
> -	return -EINVAL;
> -}
> -
> -static int uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
> -{
> -	struct uvc_fh *handle = file->private_data;
> -	struct uvc_streaming *stream = handle->stream;
> -
> -	uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
> -
> -	return uvc_queue_mmap(&stream->queue, vma);
> -}
> -
> -static __poll_t uvc_v4l2_poll(struct file *file, poll_table *wait)
> -{
> -	struct uvc_fh *handle = file->private_data;
> -	struct uvc_streaming *stream = handle->stream;
> -
> -	uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
> -
> -	return uvc_queue_poll(&stream->queue, file, wait);
> -}
> -
> -#ifndef CONFIG_MMU
> -static unsigned long uvc_v4l2_get_unmapped_area(struct file *file,
> -		unsigned long addr, unsigned long len, unsigned long pgoff,
> -		unsigned long flags)
> -{
> -	struct uvc_fh *handle = file->private_data;
> -	struct uvc_streaming *stream = handle->stream;
> -
> -	uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
> -
> -	return uvc_queue_get_unmapped_area(&stream->queue, pgoff);
> -}
> -#endif
> -
>  const struct v4l2_ioctl_ops uvc_ioctl_ops = {
>  	.vidioc_g_fmt_vid_cap = uvc_ioctl_g_fmt,
>  	.vidioc_g_fmt_vid_out = uvc_ioctl_g_fmt,
> @@ -1527,12 +1316,13 @@ const struct v4l2_ioctl_ops uvc_ioctl_ops = {
>  	.vidioc_enum_fmt_vid_out = uvc_ioctl_enum_fmt,
>  	.vidioc_try_fmt_vid_cap = uvc_ioctl_try_fmt,
>  	.vidioc_try_fmt_vid_out = uvc_ioctl_try_fmt,
> -	.vidioc_reqbufs = uvc_ioctl_reqbufs,
> -	.vidioc_querybuf = uvc_ioctl_querybuf,
> -	.vidioc_qbuf = uvc_ioctl_qbuf,
> -	.vidioc_expbuf = uvc_ioctl_expbuf,
> -	.vidioc_dqbuf = uvc_ioctl_dqbuf,
> -	.vidioc_create_bufs = uvc_ioctl_create_bufs,
> +	.vidioc_reqbufs = vb2_ioctl_reqbufs,
> +	.vidioc_querybuf = vb2_ioctl_querybuf,
> +	.vidioc_prepare_buf = vb2_ioctl_prepare_buf,
> +	.vidioc_qbuf = vb2_ioctl_qbuf,
> +	.vidioc_expbuf = vb2_ioctl_expbuf,
> +	.vidioc_dqbuf = vb2_ioctl_dqbuf,
> +	.vidioc_create_bufs = vb2_ioctl_create_bufs,
>  	.vidioc_streamon = uvc_ioctl_streamon,
>  	.vidioc_streamoff = uvc_ioctl_streamoff,
>  	.vidioc_enum_input = uvc_ioctl_enum_input,
> @@ -1559,11 +1349,10 @@ const struct v4l2_file_operations uvc_fops = {
>  #ifdef CONFIG_COMPAT
>  	.compat_ioctl32	= uvc_v4l2_compat_ioctl32,
>  #endif
> -	.read		= uvc_v4l2_read,
> -	.mmap		= uvc_v4l2_mmap,
> -	.poll		= uvc_v4l2_poll,
> +	.mmap		= vb2_fop_mmap,
> +	.poll		= vb2_fop_poll,
>  #ifndef CONFIG_MMU
> -	.get_unmapped_area = uvc_v4l2_get_unmapped_area,
> +	.get_unmapped_area = vb2_fop_get_unmapped_area,
>  #endif
>  };
>  
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index b9f8eb62ba1d82ea7788cf6c10cc838a429dbc9e..3ddbf065a2cbae40ee48cb06f84ca8f0052990c4 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -326,7 +326,10 @@ struct uvc_buffer {
>  
>  struct uvc_video_queue {
>  	struct vb2_queue queue;
> -	struct mutex mutex;			/* Protects queue */
> +	struct mutex mutex;			/*
> +						 * Serializes vb2_queue and
> +						 * fops
> +						 */
>  
>  	unsigned int flags;
>  	unsigned int buf_used;
> @@ -349,7 +352,6 @@ struct uvc_video_chain {
>  						 * uvc_fh.pending_async_ctrls
>  						 */
>  
> -	struct v4l2_prio_state prio;		/* V4L2 priority state */
>  	u32 caps;				/* V4L2 chain-wide caps */
>  	u8 ctrl_class_bitmap;			/* Bitmap of valid classes */
>  };
> @@ -619,16 +621,10 @@ struct uvc_device {
>  	struct uvc_entity *gpio_unit;
>  };
>  
> -enum uvc_handle_state {
> -	UVC_HANDLE_PASSIVE	= 0,
> -	UVC_HANDLE_ACTIVE	= 1,
> -};
> -
>  struct uvc_fh {
>  	struct v4l2_fh vfh;
>  	struct uvc_video_chain *chain;
>  	struct uvc_streaming *stream;
> -	enum uvc_handle_state state;
>  	unsigned int pending_async_ctrls;
>  	bool is_streaming;
>  };
> @@ -687,36 +683,11 @@ struct uvc_entity *uvc_entity_by_id(struct uvc_device *dev, int id);
>  
>  /* Video buffers queue management. */
>  int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type);
> -void uvc_queue_release(struct uvc_video_queue *queue);
> -int uvc_request_buffers(struct uvc_video_queue *queue,
> -			struct v4l2_requestbuffers *rb);
> -int uvc_query_buffer(struct uvc_video_queue *queue,
> -		     struct v4l2_buffer *v4l2_buf);
> -int uvc_create_buffers(struct uvc_video_queue *queue,
> -		       struct v4l2_create_buffers *v4l2_cb);
> -int uvc_queue_buffer(struct uvc_video_queue *queue,
> -		     struct media_device *mdev,
> -		     struct v4l2_buffer *v4l2_buf);
> -int uvc_export_buffer(struct uvc_video_queue *queue,
> -		      struct v4l2_exportbuffer *exp);
> -int uvc_dequeue_buffer(struct uvc_video_queue *queue,
> -		       struct v4l2_buffer *v4l2_buf, int nonblocking);
> -int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type);
> -int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type);
>  void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect);
>  struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
>  					 struct uvc_buffer *buf);
>  struct uvc_buffer *uvc_queue_get_current_buffer(struct uvc_video_queue *queue);
>  void uvc_queue_buffer_release(struct uvc_buffer *buf);
> -int uvc_queue_mmap(struct uvc_video_queue *queue,
> -		   struct vm_area_struct *vma);
> -__poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
> -			poll_table *wait);
> -#ifndef CONFIG_MMU
> -unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
> -					  unsigned long pgoff);
> -#endif
> -int uvc_queue_allocated(struct uvc_video_queue *queue);
>  static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
>  {
>  	return vb2_is_streaming(&queue->queue);
> 

Re: [PATCH 2/3] media: uvcvideo: Use vb2 ioctl and fop helpers

[Hans de Goede]

Hi,

On 26-May-25 16:16, Hans de Goede wrote:
> Hi,
> 
> On 22-May-25 19:58, Ricardo Ribalda wrote:
>> From: Hans Verkuil <hans@jjverkuil.nl>
>>
>> When uvc was written the vb2 ioctl and file operation helpers didn't exist.
>>
>> This patch switches uvc over to those helpers, which removes a lot of
>> boilerplatecode and simplifies VIDIOC_G/S_PRIORITY handling and allows us
>> to drop the 'privileges' scheme, since that's now handled inside the vb2
>> helpers.
>>
>> This makes it possible for uvc to fix the v4l2-compliance streaming tests:
>>  warn: v4l2-test-formats.cpp(1075): Could not set fmt2
>>
>> This patch introduces a change on behavior on the uvcdriver to be
>> aligned with the rest of the subsystem. Now S_INPUT, S_PARM and
>> S_FORMAT do no gran exclusive ownership of the device.
>>
>> Signed-off-by: Hans Verkuil <hans@jjverkuil.nl>
>> Co-developed-by: Ricardo Ribalda <ribalda@chromium.org>
>> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> 
> Thanks, patch looks good to me:
> 
> Reviewed-by: Hans de Goede <hansg@kernel.org>

p.s.

The review is mostly for the code changes, this changes does have
userspace API aspects also. Now multiple processes will be able
to do say set_fmt or s_input at the same time until buffers
are requsted.

I don't think this will really be an issue, but it is something
which requires careful consideration before merging this.


> Regards,
> 
> Hans
> 
>> ---
>>  drivers/media/usb/uvc/uvc_driver.c   |  34 +----
>>  drivers/media/usb/uvc/uvc_metadata.c |   8 +-
>>  drivers/media/usb/uvc/uvc_queue.c    | 143 --------------------
>>  drivers/media/usb/uvc/uvc_v4l2.c     | 251 +++--------------------------------
>>  drivers/media/usb/uvc/uvcvideo.h     |  37 +-----
>>  5 files changed, 30 insertions(+), 443 deletions(-)
>>
>> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
>> index da24a655ab68cc0957762f2b67387677c22224d1..4eeedab93b90939fc4c925012a18b7d018ade39f 100644
>> --- a/drivers/media/usb/uvc/uvc_driver.c
>> +++ b/drivers/media/usb/uvc/uvc_driver.c
>> @@ -1725,7 +1725,6 @@ static struct uvc_video_chain *uvc_alloc_chain(struct uvc_device *dev)
>>  	INIT_LIST_HEAD(&chain->entities);
>>  	mutex_init(&chain->ctrl_mutex);
>>  	chain->dev = dev;
>> -	v4l2_prio_init(&chain->prio);
>>  
>>  	return chain;
>>  }
>> @@ -1958,31 +1957,7 @@ static void uvc_unregister_video(struct uvc_device *dev)
>>  		if (!video_is_registered(&stream->vdev))
>>  			continue;
>>  
>> -		/*
>> -		 * For stream->vdev we follow the same logic as:
>> -		 * vb2_video_unregister_device().
>> -		 */
>> -
>> -		/* 1. Take a reference to vdev */
>> -		get_device(&stream->vdev.dev);
>> -
>> -		/* 2. Ensure that no new ioctls can be called. */
>> -		video_unregister_device(&stream->vdev);
>> -
>> -		/* 3. Wait for old ioctls to finish. */
>> -		mutex_lock(&stream->mutex);
>> -
>> -		/* 4. Stop streaming. */
>> -		uvc_queue_release(&stream->queue);
>> -
>> -		mutex_unlock(&stream->mutex);
>> -
>> -		put_device(&stream->vdev.dev);
>> -
>> -		/*
>> -		 * For stream->meta.vdev we can directly call:
>> -		 * vb2_video_unregister_device().
>> -		 */
>> +		vb2_video_unregister_device(&stream->vdev);
>>  		vb2_video_unregister_device(&stream->meta.vdev);
>>  
>>  		/*
>> @@ -2029,7 +2004,8 @@ int uvc_register_video_device(struct uvc_device *dev,
>>  	vdev->fops = fops;
>>  	vdev->ioctl_ops = ioctl_ops;
>>  	vdev->release = uvc_release;
>> -	vdev->prio = &stream->chain->prio;
>> +	vdev->queue = &queue->queue;
>> +	vdev->lock = &queue->mutex;
>>  	if (type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
>>  		vdev->vfl_dir = VFL_DIR_TX;
>>  	else
>> @@ -2399,8 +2375,8 @@ static int __uvc_resume(struct usb_interface *intf, int reset)
>>  		if (stream->intf == intf) {
>>  			ret = uvc_video_resume(stream, reset);
>>  			if (ret < 0)
>> -				uvc_queue_streamoff(&stream->queue,
>> -						    stream->queue.queue.type);
>> +				vb2_streamoff(&stream->queue.queue,
>> +					      stream->queue.queue.type);
>>  			return ret;
>>  		}
>>  	}
>> diff --git a/drivers/media/usb/uvc/uvc_metadata.c b/drivers/media/usb/uvc/uvc_metadata.c
>> index 82de7781f5b6b70c5ba16bcba9e0741231231904..d3aab22f91cea21aefc56409924dfa1451aec914 100644
>> --- a/drivers/media/usb/uvc/uvc_metadata.c
>> +++ b/drivers/media/usb/uvc/uvc_metadata.c
>> @@ -96,7 +96,7 @@ static int uvc_meta_v4l2_set_format(struct file *file, void *fh,
>>  	 */
>>  	mutex_lock(&stream->mutex);
>>  
>> -	if (uvc_queue_allocated(&stream->queue))
>> +	if (vb2_is_busy(&stream->meta.queue.queue))
>>  		ret = -EBUSY;
>>  	else
>>  		stream->meta.format = fmt->dataformat;
>> @@ -164,12 +164,6 @@ int uvc_meta_register(struct uvc_streaming *stream)
>>  
>>  	stream->meta.format = V4L2_META_FMT_UVC;
>>  
>> -	/*
>> -	 * The video interface queue uses manual locking and thus does not set
>> -	 * the queue pointer. Set it manually here.
>> -	 */
>> -	vdev->queue = &queue->queue;
>> -
>>  	return uvc_register_video_device(dev, stream, vdev, queue,
>>  					 V4L2_BUF_TYPE_META_CAPTURE,
>>  					 &uvc_meta_fops, &uvc_meta_ioctl_ops);
>> diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
>> index 2ee142621042167c2587b6a6fdd51c1a46d31c11..72c5494dee9f46ff61072e7d293bfaddda40e615 100644
>> --- a/drivers/media/usb/uvc/uvc_queue.c
>> +++ b/drivers/media/usb/uvc/uvc_queue.c
>> @@ -242,153 +242,10 @@ int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type)
>>  	return 0;
>>  }
>>  
>> -void uvc_queue_release(struct uvc_video_queue *queue)
>> -{
>> -	mutex_lock(&queue->mutex);
>> -	vb2_queue_release(&queue->queue);
>> -	mutex_unlock(&queue->mutex);
>> -}
>> -
>> -/* -----------------------------------------------------------------------------
>> - * V4L2 queue operations
>> - */
>> -
>> -int uvc_request_buffers(struct uvc_video_queue *queue,
>> -			struct v4l2_requestbuffers *rb)
>> -{
>> -	int ret;
>> -
>> -	mutex_lock(&queue->mutex);
>> -	ret = vb2_reqbufs(&queue->queue, rb);
>> -	mutex_unlock(&queue->mutex);
>> -
>> -	return ret ? ret : rb->count;
>> -}
>> -
>> -int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
>> -{
>> -	int ret;
>> -
>> -	mutex_lock(&queue->mutex);
>> -	ret = vb2_querybuf(&queue->queue, buf);
>> -	mutex_unlock(&queue->mutex);
>> -
>> -	return ret;
>> -}
>> -
>> -int uvc_create_buffers(struct uvc_video_queue *queue,
>> -		       struct v4l2_create_buffers *cb)
>> -{
>> -	int ret;
>> -
>> -	mutex_lock(&queue->mutex);
>> -	ret = vb2_create_bufs(&queue->queue, cb);
>> -	mutex_unlock(&queue->mutex);
>> -
>> -	return ret;
>> -}
>> -
>> -int uvc_queue_buffer(struct uvc_video_queue *queue,
>> -		     struct media_device *mdev, struct v4l2_buffer *buf)
>> -{
>> -	int ret;
>> -
>> -	mutex_lock(&queue->mutex);
>> -	ret = vb2_qbuf(&queue->queue, mdev, buf);
>> -	mutex_unlock(&queue->mutex);
>> -
>> -	return ret;
>> -}
>> -
>> -int uvc_export_buffer(struct uvc_video_queue *queue,
>> -		      struct v4l2_exportbuffer *exp)
>> -{
>> -	int ret;
>> -
>> -	mutex_lock(&queue->mutex);
>> -	ret = vb2_expbuf(&queue->queue, exp);
>> -	mutex_unlock(&queue->mutex);
>> -
>> -	return ret;
>> -}
>> -
>> -int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
>> -		       int nonblocking)
>> -{
>> -	int ret;
>> -
>> -	mutex_lock(&queue->mutex);
>> -	ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
>> -	mutex_unlock(&queue->mutex);
>> -
>> -	return ret;
>> -}
>> -
>> -int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type)
>> -{
>> -	int ret;
>> -
>> -	mutex_lock(&queue->mutex);
>> -	ret = vb2_streamon(&queue->queue, type);
>> -	mutex_unlock(&queue->mutex);
>> -
>> -	return ret;
>> -}
>> -
>> -int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type)
>> -{
>> -	int ret;
>> -
>> -	mutex_lock(&queue->mutex);
>> -	ret = vb2_streamoff(&queue->queue, type);
>> -	mutex_unlock(&queue->mutex);
>> -
>> -	return ret;
>> -}
>> -
>> -int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
>> -{
>> -	return vb2_mmap(&queue->queue, vma);
>> -}
>> -
>> -#ifndef CONFIG_MMU
>> -unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
>> -		unsigned long pgoff)
>> -{
>> -	return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
>> -}
>> -#endif
>> -
>> -__poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
>> -			    poll_table *wait)
>> -{
>> -	__poll_t ret;
>> -
>> -	mutex_lock(&queue->mutex);
>> -	ret = vb2_poll(&queue->queue, file, wait);
>> -	mutex_unlock(&queue->mutex);
>> -
>> -	return ret;
>> -}
>> -
>>  /* -----------------------------------------------------------------------------
>>   *
>>   */
>>  
>> -/*
>> - * Check if buffers have been allocated.
>> - */
>> -int uvc_queue_allocated(struct uvc_video_queue *queue)
>> -{
>> -	int allocated;
>> -
>> -	mutex_lock(&queue->mutex);
>> -	allocated = vb2_is_busy(&queue->queue);
>> -	mutex_unlock(&queue->mutex);
>> -
>> -	return allocated;
>> -}
>> -
>>  /*
>>   * Cancel the video buffers queue.
>>   *
>> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
>> index 862b4e34e5b629cf324479a9bb59ebe8784ccd5d..7a5ecbefa32c0a6b74c85d7f77a25b433598471e 100644
>> --- a/drivers/media/usb/uvc/uvc_v4l2.c
>> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
>> @@ -47,8 +47,6 @@ void uvc_pm_put(struct uvc_device *dev)
>>  	usb_autopm_put_interface(dev->intf);
>>  }
>>  
>> -static int uvc_acquire_privileges(struct uvc_fh *handle);
>> -
>>  static int uvc_control_add_xu_mapping(struct uvc_video_chain *chain,
>>  				      struct uvc_control_mapping *map,
>>  				      const struct uvc_xu_control_mapping *xmap)
>> @@ -436,10 +434,6 @@ static int uvc_ioctl_s_fmt(struct file *file, void *fh,
>>  	const struct uvc_frame *frame;
>>  	int ret;
>>  
>> -	ret = uvc_acquire_privileges(handle);
>> -	if (ret < 0)
>> -		return ret;
>> -
>>  	if (fmt->type != stream->type)
>>  		return -EINVAL;
>>  
>> @@ -448,8 +442,7 @@ static int uvc_ioctl_s_fmt(struct file *file, void *fh,
>>  		return ret;
>>  
>>  	mutex_lock(&stream->mutex);
>> -
>> -	if (uvc_queue_allocated(&stream->queue)) {
>> +	if (vb2_is_busy(&stream->queue.queue)) {
>>  		ret = -EBUSY;
>>  		goto done;
>>  	}
>> @@ -513,10 +506,6 @@ static int uvc_ioctl_s_parm(struct file *file, void *fh,
>>  	unsigned int i;
>>  	int ret;
>>  
>> -	ret = uvc_acquire_privileges(handle);
>> -	if (ret < 0)
>> -		return ret;
>> -
>>  	if (parm->type != stream->type)
>>  		return -EINVAL;
>>  
>> @@ -593,63 +582,6 @@ static int uvc_ioctl_s_parm(struct file *file, void *fh,
>>  	return 0;
>>  }
>>  
>> -/* ------------------------------------------------------------------------
>> - * Privilege management
>> - */
>> -
>> -/*
>> - * Privilege management is the multiple-open implementation basis. The current
>> - * implementation is completely transparent for the end-user and doesn't
>> - * require explicit use of the VIDIOC_G_PRIORITY and VIDIOC_S_PRIORITY ioctls.
>> - * Those ioctls enable finer control on the device (by making possible for a
>> - * user to request exclusive access to a device), but are not mature yet.
>> - * Switching to the V4L2 priority mechanism might be considered in the future
>> - * if this situation changes.
>> - *
>> - * Each open instance of a UVC device can either be in a privileged or
>> - * unprivileged state. Only a single instance can be in a privileged state at
>> - * a given time. Trying to perform an operation that requires privileges will
>> - * automatically acquire the required privileges if possible, or return -EBUSY
>> - * otherwise. Privileges are dismissed when closing the instance or when
>> - * freeing the video buffers using VIDIOC_REQBUFS.
>> - *
>> - * Operations that require privileges are:
>> - *
>> - * - VIDIOC_S_INPUT
>> - * - VIDIOC_S_PARM
>> - * - VIDIOC_S_FMT
>> - * - VIDIOC_CREATE_BUFS
>> - * - VIDIOC_REQBUFS
>> - */
>> -static int uvc_acquire_privileges(struct uvc_fh *handle)
>> -{
>> -	/* Always succeed if the handle is already privileged. */
>> -	if (handle->state == UVC_HANDLE_ACTIVE)
>> -		return 0;
>> -
>> -	/* Check if the device already has a privileged handle. */
>> -	if (atomic_inc_return(&handle->stream->active) != 1) {
>> -		atomic_dec(&handle->stream->active);
>> -		return -EBUSY;
>> -	}
>> -
>> -	handle->state = UVC_HANDLE_ACTIVE;
>> -	return 0;
>> -}
>> -
>> -static void uvc_dismiss_privileges(struct uvc_fh *handle)
>> -{
>> -	if (handle->state == UVC_HANDLE_ACTIVE)
>> -		atomic_dec(&handle->stream->active);
>> -
>> -	handle->state = UVC_HANDLE_PASSIVE;
>> -}
>> -
>> -static int uvc_has_privileges(struct uvc_fh *handle)
>> -{
>> -	return handle->state == UVC_HANDLE_ACTIVE;
>> -}
>> -
>>  /* ------------------------------------------------------------------------
>>   * V4L2 file operations
>>   */
>> @@ -671,7 +603,6 @@ static int uvc_v4l2_open(struct file *file)
>>  	v4l2_fh_add(&handle->vfh);
>>  	handle->chain = stream->chain;
>>  	handle->stream = stream;
>> -	handle->state = UVC_HANDLE_PASSIVE;
>>  	file->private_data = handle;
>>  
>>  	return 0;
>> @@ -686,18 +617,11 @@ static int uvc_v4l2_release(struct file *file)
>>  
>>  	uvc_ctrl_cleanup_fh(handle);
>>  
>> -	/* Only free resources if this is a privileged handle. */
>> -	if (uvc_has_privileges(handle))
>> -		uvc_queue_release(&stream->queue);
>> -
>>  	if (handle->is_streaming)
>>  		uvc_pm_put(stream->dev);
>>  
>>  	/* Release the file handle. */
>> -	uvc_dismiss_privileges(handle);
>> -	v4l2_fh_del(&handle->vfh);
>> -	v4l2_fh_exit(&handle->vfh);
>> -	kfree(handle);
>> +	vb2_fop_release(file);
>>  	file->private_data = NULL;
>>  
>>  	return 0;
>> @@ -753,91 +677,6 @@ static int uvc_ioctl_try_fmt(struct file *file, void *fh,
>>  	return uvc_v4l2_try_format(stream, fmt, &probe, NULL, NULL);
>>  }
>>  
>> -static int uvc_ioctl_reqbufs(struct file *file, void *fh,
>> -			     struct v4l2_requestbuffers *rb)
>> -{
>> -	struct uvc_fh *handle = fh;
>> -	struct uvc_streaming *stream = handle->stream;
>> -	int ret;
>> -
>> -	ret = uvc_acquire_privileges(handle);
>> -	if (ret < 0)
>> -		return ret;
>> -
>> -	mutex_lock(&stream->mutex);
>> -	ret = uvc_request_buffers(&stream->queue, rb);
>> -	mutex_unlock(&stream->mutex);
>> -	if (ret < 0)
>> -		return ret;
>> -
>> -	if (ret == 0)
>> -		uvc_dismiss_privileges(handle);
>> -
>> -	return 0;
>> -}
>> -
>> -static int uvc_ioctl_querybuf(struct file *file, void *fh,
>> -			      struct v4l2_buffer *buf)
>> -{
>> -	struct uvc_fh *handle = fh;
>> -	struct uvc_streaming *stream = handle->stream;
>> -
>> -	if (!uvc_has_privileges(handle))
>> -		return -EBUSY;
>> -
>> -	return uvc_query_buffer(&stream->queue, buf);
>> -}
>> -
>> -static int uvc_ioctl_qbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
>> -{
>> -	struct uvc_fh *handle = fh;
>> -	struct uvc_streaming *stream = handle->stream;
>> -
>> -	if (!uvc_has_privileges(handle))
>> -		return -EBUSY;
>> -
>> -	return uvc_queue_buffer(&stream->queue,
>> -				stream->vdev.v4l2_dev->mdev, buf);
>> -}
>> -
>> -static int uvc_ioctl_expbuf(struct file *file, void *fh,
>> -			    struct v4l2_exportbuffer *exp)
>> -{
>> -	struct uvc_fh *handle = fh;
>> -	struct uvc_streaming *stream = handle->stream;
>> -
>> -	if (!uvc_has_privileges(handle))
>> -		return -EBUSY;
>> -
>> -	return uvc_export_buffer(&stream->queue, exp);
>> -}
>> -
>> -static int uvc_ioctl_dqbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
>> -{
>> -	struct uvc_fh *handle = fh;
>> -	struct uvc_streaming *stream = handle->stream;
>> -
>> -	if (!uvc_has_privileges(handle))
>> -		return -EBUSY;
>> -
>> -	return uvc_dequeue_buffer(&stream->queue, buf,
>> -				  file->f_flags & O_NONBLOCK);
>> -}
>> -
>> -static int uvc_ioctl_create_bufs(struct file *file, void *fh,
>> -				  struct v4l2_create_buffers *cb)
>> -{
>> -	struct uvc_fh *handle = fh;
>> -	struct uvc_streaming *stream = handle->stream;
>> -	int ret;
>> -
>> -	ret = uvc_acquire_privileges(handle);
>> -	if (ret < 0)
>> -		return ret;
>> -
>> -	return uvc_create_buffers(&stream->queue, cb);
>> -}
>> -
>>  static int uvc_ioctl_streamon(struct file *file, void *fh,
>>  			      enum v4l2_buf_type type)
>>  {
>> @@ -845,11 +684,6 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
>>  	struct uvc_streaming *stream = handle->stream;
>>  	int ret;
>>  
>> -	if (!uvc_has_privileges(handle))
>> -		return -EBUSY;
>> -
>> -	guard(mutex)(&stream->mutex);
>> -
>>  	if (handle->is_streaming)
>>  		return 0;
>>  
>> @@ -857,7 +691,7 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
>>  	if (ret)
>>  		return ret;
>>  
>> -	ret = uvc_queue_streamon(&stream->queue, type);
>> +	ret = vb2_ioctl_streamon(file, fh, type);
>>  	if (ret) {
>>  		uvc_pm_put(stream->dev);
>>  		return ret;
>> @@ -873,13 +707,12 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
>>  {
>>  	struct uvc_fh *handle = fh;
>>  	struct uvc_streaming *stream = handle->stream;
>> +	int ret;
>>  
>> -	if (!uvc_has_privileges(handle))
>> -		return -EBUSY;
>> -
>> -	guard(mutex)(&stream->mutex);
>> +	ret = vb2_ioctl_streamoff(file, fh, type);
>> +	if (ret)
>> +		return ret;
>>  
>> -	uvc_queue_streamoff(&stream->queue, type);
>>  	if (handle->is_streaming) {
>>  		handle->is_streaming = false;
>>  		uvc_pm_put(stream->dev);
>> @@ -962,13 +795,13 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
>>  static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
>>  {
>>  	struct uvc_fh *handle = fh;
>> +	struct uvc_streaming *stream = handle->stream;
>>  	struct uvc_video_chain *chain = handle->chain;
>>  	u8 *buf;
>>  	int ret;
>>  
>> -	ret = uvc_acquire_privileges(handle);
>> -	if (ret < 0)
>> -		return ret;
>> +	if (vb2_is_busy(&stream->queue.queue))
>> +		return -EBUSY;
>>  
>>  	if (chain->selector == NULL ||
>>  	    (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
>> @@ -1471,50 +1304,6 @@ static long uvc_v4l2_unlocked_ioctl(struct file *file,
>>  	return ret;
>>  }
>>  
>> -static ssize_t uvc_v4l2_read(struct file *file, char __user *data,
>> -		    size_t count, loff_t *ppos)
>> -{
>> -	struct uvc_fh *handle = file->private_data;
>> -	struct uvc_streaming *stream = handle->stream;
>> -
>> -	uvc_dbg(stream->dev, CALLS, "%s: not implemented\n", __func__);
>> -	return -EINVAL;
>> -}
>> -
>> -static int uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
>> -{
>> -	struct uvc_fh *handle = file->private_data;
>> -	struct uvc_streaming *stream = handle->stream;
>> -
>> -	uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
>> -
>> -	return uvc_queue_mmap(&stream->queue, vma);
>> -}
>> -
>> -static __poll_t uvc_v4l2_poll(struct file *file, poll_table *wait)
>> -{
>> -	struct uvc_fh *handle = file->private_data;
>> -	struct uvc_streaming *stream = handle->stream;
>> -
>> -	uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
>> -
>> -	return uvc_queue_poll(&stream->queue, file, wait);
>> -}
>> -
>> -#ifndef CONFIG_MMU
>> -static unsigned long uvc_v4l2_get_unmapped_area(struct file *file,
>> -		unsigned long addr, unsigned long len, unsigned long pgoff,
>> -		unsigned long flags)
>> -{
>> -	struct uvc_fh *handle = file->private_data;
>> -	struct uvc_streaming *stream = handle->stream;
>> -
>> -	uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
>> -
>> -	return uvc_queue_get_unmapped_area(&stream->queue, pgoff);
>> -}
>> -#endif
>> -
>>  const struct v4l2_ioctl_ops uvc_ioctl_ops = {
>>  	.vidioc_g_fmt_vid_cap = uvc_ioctl_g_fmt,
>>  	.vidioc_g_fmt_vid_out = uvc_ioctl_g_fmt,
>> @@ -1527,12 +1316,13 @@ const struct v4l2_ioctl_ops uvc_ioctl_ops = {
>>  	.vidioc_enum_fmt_vid_out = uvc_ioctl_enum_fmt,
>>  	.vidioc_try_fmt_vid_cap = uvc_ioctl_try_fmt,
>>  	.vidioc_try_fmt_vid_out = uvc_ioctl_try_fmt,
>> -	.vidioc_reqbufs = uvc_ioctl_reqbufs,
>> -	.vidioc_querybuf = uvc_ioctl_querybuf,
>> -	.vidioc_qbuf = uvc_ioctl_qbuf,
>> -	.vidioc_expbuf = uvc_ioctl_expbuf,
>> -	.vidioc_dqbuf = uvc_ioctl_dqbuf,
>> -	.vidioc_create_bufs = uvc_ioctl_create_bufs,
>> +	.vidioc_reqbufs = vb2_ioctl_reqbufs,
>> +	.vidioc_querybuf = vb2_ioctl_querybuf,
>> +	.vidioc_prepare_buf = vb2_ioctl_prepare_buf,
>> +	.vidioc_qbuf = vb2_ioctl_qbuf,
>> +	.vidioc_expbuf = vb2_ioctl_expbuf,
>> +	.vidioc_dqbuf = vb2_ioctl_dqbuf,
>> +	.vidioc_create_bufs = vb2_ioctl_create_bufs,
>>  	.vidioc_streamon = uvc_ioctl_streamon,
>>  	.vidioc_streamoff = uvc_ioctl_streamoff,
>>  	.vidioc_enum_input = uvc_ioctl_enum_input,
>> @@ -1559,11 +1349,10 @@ const struct v4l2_file_operations uvc_fops = {
>>  #ifdef CONFIG_COMPAT
>>  	.compat_ioctl32	= uvc_v4l2_compat_ioctl32,
>>  #endif
>> -	.read		= uvc_v4l2_read,
>> -	.mmap		= uvc_v4l2_mmap,
>> -	.poll		= uvc_v4l2_poll,
>> +	.mmap		= vb2_fop_mmap,
>> +	.poll		= vb2_fop_poll,
>>  #ifndef CONFIG_MMU
>> -	.get_unmapped_area = uvc_v4l2_get_unmapped_area,
>> +	.get_unmapped_area = vb2_fop_get_unmapped_area,
>>  #endif
>>  };
>>  
>> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
>> index b9f8eb62ba1d82ea7788cf6c10cc838a429dbc9e..3ddbf065a2cbae40ee48cb06f84ca8f0052990c4 100644
>> --- a/drivers/media/usb/uvc/uvcvideo.h
>> +++ b/drivers/media/usb/uvc/uvcvideo.h
>> @@ -326,7 +326,10 @@ struct uvc_buffer {
>>  
>>  struct uvc_video_queue {
>>  	struct vb2_queue queue;
>> -	struct mutex mutex;			/* Protects queue */
>> +	struct mutex mutex;			/*
>> +						 * Serializes vb2_queue and
>> +						 * fops
>> +						 */
>>  
>>  	unsigned int flags;
>>  	unsigned int buf_used;
>> @@ -349,7 +352,6 @@ struct uvc_video_chain {
>>  						 * uvc_fh.pending_async_ctrls
>>  						 */
>>  
>> -	struct v4l2_prio_state prio;		/* V4L2 priority state */
>>  	u32 caps;				/* V4L2 chain-wide caps */
>>  	u8 ctrl_class_bitmap;			/* Bitmap of valid classes */
>>  };
>> @@ -619,16 +621,10 @@ struct uvc_device {
>>  	struct uvc_entity *gpio_unit;
>>  };
>>  
>> -enum uvc_handle_state {
>> -	UVC_HANDLE_PASSIVE	= 0,
>> -	UVC_HANDLE_ACTIVE	= 1,
>> -};
>> -
>>  struct uvc_fh {
>>  	struct v4l2_fh vfh;
>>  	struct uvc_video_chain *chain;
>>  	struct uvc_streaming *stream;
>> -	enum uvc_handle_state state;
>>  	unsigned int pending_async_ctrls;
>>  	bool is_streaming;
>>  };
>> @@ -687,36 +683,11 @@ struct uvc_entity *uvc_entity_by_id(struct uvc_device *dev, int id);
>>  
>>  /* Video buffers queue management. */
>>  int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type);
>> -void uvc_queue_release(struct uvc_video_queue *queue);
>> -int uvc_request_buffers(struct uvc_video_queue *queue,
>> -			struct v4l2_requestbuffers *rb);
>> -int uvc_query_buffer(struct uvc_video_queue *queue,
>> -		     struct v4l2_buffer *v4l2_buf);
>> -int uvc_create_buffers(struct uvc_video_queue *queue,
>> -		       struct v4l2_create_buffers *v4l2_cb);
>> -int uvc_queue_buffer(struct uvc_video_queue *queue,
>> -		     struct media_device *mdev,
>> -		     struct v4l2_buffer *v4l2_buf);
>> -int uvc_export_buffer(struct uvc_video_queue *queue,
>> -		      struct v4l2_exportbuffer *exp);
>> -int uvc_dequeue_buffer(struct uvc_video_queue *queue,
>> -		       struct v4l2_buffer *v4l2_buf, int nonblocking);
>> -int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type);
>> -int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type);
>>  void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect);
>>  struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
>>  					 struct uvc_buffer *buf);
>>  struct uvc_buffer *uvc_queue_get_current_buffer(struct uvc_video_queue *queue);
>>  void uvc_queue_buffer_release(struct uvc_buffer *buf);
>> -int uvc_queue_mmap(struct uvc_video_queue *queue,
>> -		   struct vm_area_struct *vma);
>> -__poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
>> -			poll_table *wait);
>> -#ifndef CONFIG_MMU
>> -unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
>> -					  unsigned long pgoff);
>> -#endif
>> -int uvc_queue_allocated(struct uvc_video_queue *queue);
>>  static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
>>  {
>>  	return vb2_is_streaming(&queue->queue);
>>
> 
> 

Re: [PATCH 1/3] media: uvcvideo: Refactor uvc_queue_streamon

[Hans Verkuil]

On 22/05/2025 19:58, Ricardo Ribalda wrote:
> Do uvc_pm_get before we call uvc_queue_streamon. Although the current
> code is correct, uvc_ioctl_streamon is allways called after uvc_pm_get,

allways -> always

> this change makes the code more resiliant to future changes.

I would add that this change also avoids calling streamoff, which is
a rather ugly thing to do.

> 
> Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>

Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>

Regards,

	Hans

> ---
>  drivers/media/usb/uvc/uvc_v4l2.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> index 668a4e9d772c6d91f045ca75e2744b3a6c69da6b..862b4e34e5b629cf324479a9bb59ebe8784ccd5d 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -853,15 +853,16 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
>  	if (handle->is_streaming)
>  		return 0;
>  
> -	ret = uvc_queue_streamon(&stream->queue, type);
> +	ret = uvc_pm_get(stream->dev);
>  	if (ret)
>  		return ret;
>  
> -	ret = uvc_pm_get(stream->dev);
> +	ret = uvc_queue_streamon(&stream->queue, type);
>  	if (ret) {
> -		uvc_queue_streamoff(&stream->queue, type);
> +		uvc_pm_put(stream->dev);
>  		return ret;
>  	}
> +
>  	handle->is_streaming = true;
>  
>  	return 0;
> 

Re: [PATCH 2/3] media: uvcvideo: Use vb2 ioctl and fop helpers

[Hans Verkuil]

On 22/05/2025 19:58, Ricardo Ribalda wrote:
> From: Hans Verkuil <hans@jjverkuil.nl>
> 
> When uvc was written the vb2 ioctl and file operation helpers didn't exist.
> 
> This patch switches uvc over to those helpers, which removes a lot of
> boilerplatecode and simplifies VIDIOC_G/S_PRIORITY handling and allows us

boilerplate code

> to drop the 'privileges' scheme, since that's now handled inside the vb2
> helpers.
> 
> This makes it possible for uvc to fix the v4l2-compliance streaming tests:
>  warn: v4l2-test-formats.cpp(1075): Could not set fmt2
> 
> This patch introduces a change on behavior on the uvcdriver to be
> aligned with the rest of the subsystem. Now S_INPUT, S_PARM and
> S_FORMAT do no gran exclusive ownership of the device.

gran -> grant

> 
> Signed-off-by: Hans Verkuil <hans@jjverkuil.nl>
> Co-developed-by: Ricardo Ribalda <ribalda@chromium.org>
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
>  drivers/media/usb/uvc/uvc_driver.c   |  34 +----
>  drivers/media/usb/uvc/uvc_metadata.c |   8 +-
>  drivers/media/usb/uvc/uvc_queue.c    | 143 --------------------
>  drivers/media/usb/uvc/uvc_v4l2.c     | 251 +++--------------------------------
>  drivers/media/usb/uvc/uvcvideo.h     |  37 +-----
>  5 files changed, 30 insertions(+), 443 deletions(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> index da24a655ab68cc0957762f2b67387677c22224d1..4eeedab93b90939fc4c925012a18b7d018ade39f 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -1725,7 +1725,6 @@ static struct uvc_video_chain *uvc_alloc_chain(struct uvc_device *dev)
>  	INIT_LIST_HEAD(&chain->entities);
>  	mutex_init(&chain->ctrl_mutex);
>  	chain->dev = dev;
> -	v4l2_prio_init(&chain->prio);
>  
>  	return chain;
>  }
> @@ -1958,31 +1957,7 @@ static void uvc_unregister_video(struct uvc_device *dev)
>  		if (!video_is_registered(&stream->vdev))
>  			continue;
>  
> -		/*
> -		 * For stream->vdev we follow the same logic as:
> -		 * vb2_video_unregister_device().
> -		 */
> -
> -		/* 1. Take a reference to vdev */
> -		get_device(&stream->vdev.dev);
> -
> -		/* 2. Ensure that no new ioctls can be called. */
> -		video_unregister_device(&stream->vdev);
> -
> -		/* 3. Wait for old ioctls to finish. */
> -		mutex_lock(&stream->mutex);
> -
> -		/* 4. Stop streaming. */
> -		uvc_queue_release(&stream->queue);
> -
> -		mutex_unlock(&stream->mutex);
> -
> -		put_device(&stream->vdev.dev);
> -
> -		/*
> -		 * For stream->meta.vdev we can directly call:
> -		 * vb2_video_unregister_device().
> -		 */
> +		vb2_video_unregister_device(&stream->vdev);

Lovely! :-)

>  		vb2_video_unregister_device(&stream->meta.vdev);
>  
>  		/*
> @@ -2029,7 +2004,8 @@ int uvc_register_video_device(struct uvc_device *dev,
>  	vdev->fops = fops;
>  	vdev->ioctl_ops = ioctl_ops;
>  	vdev->release = uvc_release;
> -	vdev->prio = &stream->chain->prio;
> +	vdev->queue = &queue->queue;
> +	vdev->lock = &queue->mutex;
>  	if (type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
>  		vdev->vfl_dir = VFL_DIR_TX;
>  	else
> @@ -2399,8 +2375,8 @@ static int __uvc_resume(struct usb_interface *intf, int reset)
>  		if (stream->intf == intf) {
>  			ret = uvc_video_resume(stream, reset);
>  			if (ret < 0)
> -				uvc_queue_streamoff(&stream->queue,
> -						    stream->queue.queue.type);
> +				vb2_streamoff(&stream->queue.queue,
> +					      stream->queue.queue.type);
>  			return ret;
>  		}
>  	}
> diff --git a/drivers/media/usb/uvc/uvc_metadata.c b/drivers/media/usb/uvc/uvc_metadata.c
> index 82de7781f5b6b70c5ba16bcba9e0741231231904..d3aab22f91cea21aefc56409924dfa1451aec914 100644
> --- a/drivers/media/usb/uvc/uvc_metadata.c
> +++ b/drivers/media/usb/uvc/uvc_metadata.c
> @@ -96,7 +96,7 @@ static int uvc_meta_v4l2_set_format(struct file *file, void *fh,
>  	 */
>  	mutex_lock(&stream->mutex);
>  
> -	if (uvc_queue_allocated(&stream->queue))
> +	if (vb2_is_busy(&stream->meta.queue.queue))
>  		ret = -EBUSY;
>  	else
>  		stream->meta.format = fmt->dataformat;
> @@ -164,12 +164,6 @@ int uvc_meta_register(struct uvc_streaming *stream)
>  
>  	stream->meta.format = V4L2_META_FMT_UVC;
>  
> -	/*
> -	 * The video interface queue uses manual locking and thus does not set
> -	 * the queue pointer. Set it manually here.
> -	 */
> -	vdev->queue = &queue->queue;
> -
>  	return uvc_register_video_device(dev, stream, vdev, queue,
>  					 V4L2_BUF_TYPE_META_CAPTURE,
>  					 &uvc_meta_fops, &uvc_meta_ioctl_ops);
> diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
> index 2ee142621042167c2587b6a6fdd51c1a46d31c11..72c5494dee9f46ff61072e7d293bfaddda40e615 100644
> --- a/drivers/media/usb/uvc/uvc_queue.c
> +++ b/drivers/media/usb/uvc/uvc_queue.c
> @@ -242,153 +242,10 @@ int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type)
>  	return 0;
>  }
>  
> -void uvc_queue_release(struct uvc_video_queue *queue)
> -{
> -	mutex_lock(&queue->mutex);
> -	vb2_queue_release(&queue->queue);
> -	mutex_unlock(&queue->mutex);
> -}
> -
> -/* -----------------------------------------------------------------------------
> - * V4L2 queue operations
> - */
> -
> -int uvc_request_buffers(struct uvc_video_queue *queue,
> -			struct v4l2_requestbuffers *rb)
> -{
> -	int ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_reqbufs(&queue->queue, rb);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret ? ret : rb->count;
> -}
> -
> -int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
> -{
> -	int ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_querybuf(&queue->queue, buf);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret;
> -}
> -
> -int uvc_create_buffers(struct uvc_video_queue *queue,
> -		       struct v4l2_create_buffers *cb)
> -{
> -	int ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_create_bufs(&queue->queue, cb);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret;
> -}
> -
> -int uvc_queue_buffer(struct uvc_video_queue *queue,
> -		     struct media_device *mdev, struct v4l2_buffer *buf)
> -{
> -	int ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_qbuf(&queue->queue, mdev, buf);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret;
> -}
> -
> -int uvc_export_buffer(struct uvc_video_queue *queue,
> -		      struct v4l2_exportbuffer *exp)
> -{
> -	int ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_expbuf(&queue->queue, exp);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret;
> -}
> -
> -int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
> -		       int nonblocking)
> -{
> -	int ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret;
> -}
> -
> -int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type)
> -{
> -	int ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_streamon(&queue->queue, type);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret;
> -}
> -
> -int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type)
> -{
> -	int ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_streamoff(&queue->queue, type);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret;
> -}
> -
> -int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
> -{
> -	return vb2_mmap(&queue->queue, vma);
> -}
> -
> -#ifndef CONFIG_MMU
> -unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
> -		unsigned long pgoff)
> -{
> -	return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
> -}
> -#endif
> -
> -__poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
> -			    poll_table *wait)
> -{
> -	__poll_t ret;
> -
> -	mutex_lock(&queue->mutex);
> -	ret = vb2_poll(&queue->queue, file, wait);
> -	mutex_unlock(&queue->mutex);
> -
> -	return ret;
> -}
> -
>  /* -----------------------------------------------------------------------------
>   *
>   */
>  
> -/*
> - * Check if buffers have been allocated.
> - */
> -int uvc_queue_allocated(struct uvc_video_queue *queue)
> -{
> -	int allocated;
> -
> -	mutex_lock(&queue->mutex);
> -	allocated = vb2_is_busy(&queue->queue);
> -	mutex_unlock(&queue->mutex);
> -
> -	return allocated;
> -}
> -
>  /*
>   * Cancel the video buffers queue.
>   *
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> index 862b4e34e5b629cf324479a9bb59ebe8784ccd5d..7a5ecbefa32c0a6b74c85d7f77a25b433598471e 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -47,8 +47,6 @@ void uvc_pm_put(struct uvc_device *dev)
>  	usb_autopm_put_interface(dev->intf);
>  }
>  
> -static int uvc_acquire_privileges(struct uvc_fh *handle);
> -
>  static int uvc_control_add_xu_mapping(struct uvc_video_chain *chain,
>  				      struct uvc_control_mapping *map,
>  				      const struct uvc_xu_control_mapping *xmap)
> @@ -436,10 +434,6 @@ static int uvc_ioctl_s_fmt(struct file *file, void *fh,
>  	const struct uvc_frame *frame;
>  	int ret;
>  
> -	ret = uvc_acquire_privileges(handle);
> -	if (ret < 0)
> -		return ret;
> -
>  	if (fmt->type != stream->type)
>  		return -EINVAL;
>  
> @@ -448,8 +442,7 @@ static int uvc_ioctl_s_fmt(struct file *file, void *fh,
>  		return ret;
>  
>  	mutex_lock(&stream->mutex);
> -
> -	if (uvc_queue_allocated(&stream->queue)) {
> +	if (vb2_is_busy(&stream->queue.queue)) {
>  		ret = -EBUSY;
>  		goto done;
>  	}
> @@ -513,10 +506,6 @@ static int uvc_ioctl_s_parm(struct file *file, void *fh,
>  	unsigned int i;
>  	int ret;
>  
> -	ret = uvc_acquire_privileges(handle);
> -	if (ret < 0)
> -		return ret;
> -
>  	if (parm->type != stream->type)
>  		return -EINVAL;
>  
> @@ -593,63 +582,6 @@ static int uvc_ioctl_s_parm(struct file *file, void *fh,
>  	return 0;
>  }
>  
> -/* ------------------------------------------------------------------------
> - * Privilege management
> - */
> -
> -/*
> - * Privilege management is the multiple-open implementation basis. The current
> - * implementation is completely transparent for the end-user and doesn't
> - * require explicit use of the VIDIOC_G_PRIORITY and VIDIOC_S_PRIORITY ioctls.
> - * Those ioctls enable finer control on the device (by making possible for a
> - * user to request exclusive access to a device), but are not mature yet.
> - * Switching to the V4L2 priority mechanism might be considered in the future
> - * if this situation changes.
> - *
> - * Each open instance of a UVC device can either be in a privileged or
> - * unprivileged state. Only a single instance can be in a privileged state at
> - * a given time. Trying to perform an operation that requires privileges will
> - * automatically acquire the required privileges if possible, or return -EBUSY
> - * otherwise. Privileges are dismissed when closing the instance or when
> - * freeing the video buffers using VIDIOC_REQBUFS.
> - *
> - * Operations that require privileges are:
> - *
> - * - VIDIOC_S_INPUT
> - * - VIDIOC_S_PARM
> - * - VIDIOC_S_FMT
> - * - VIDIOC_CREATE_BUFS
> - * - VIDIOC_REQBUFS
> - */
> -static int uvc_acquire_privileges(struct uvc_fh *handle)
> -{
> -	/* Always succeed if the handle is already privileged. */
> -	if (handle->state == UVC_HANDLE_ACTIVE)
> -		return 0;
> -
> -	/* Check if the device already has a privileged handle. */
> -	if (atomic_inc_return(&handle->stream->active) != 1) {
> -		atomic_dec(&handle->stream->active);
> -		return -EBUSY;
> -	}
> -
> -	handle->state = UVC_HANDLE_ACTIVE;
> -	return 0;
> -}
> -
> -static void uvc_dismiss_privileges(struct uvc_fh *handle)
> -{
> -	if (handle->state == UVC_HANDLE_ACTIVE)
> -		atomic_dec(&handle->stream->active);
> -
> -	handle->state = UVC_HANDLE_PASSIVE;
> -}
> -
> -static int uvc_has_privileges(struct uvc_fh *handle)
> -{
> -	return handle->state == UVC_HANDLE_ACTIVE;
> -}
> -
>  /* ------------------------------------------------------------------------
>   * V4L2 file operations
>   */
> @@ -671,7 +603,6 @@ static int uvc_v4l2_open(struct file *file)
>  	v4l2_fh_add(&handle->vfh);
>  	handle->chain = stream->chain;
>  	handle->stream = stream;
> -	handle->state = UVC_HANDLE_PASSIVE;
>  	file->private_data = handle;
>  
>  	return 0;
> @@ -686,18 +617,11 @@ static int uvc_v4l2_release(struct file *file)
>  
>  	uvc_ctrl_cleanup_fh(handle);
>  
> -	/* Only free resources if this is a privileged handle. */
> -	if (uvc_has_privileges(handle))
> -		uvc_queue_release(&stream->queue);
> -
>  	if (handle->is_streaming)
>  		uvc_pm_put(stream->dev);
>  
>  	/* Release the file handle. */
> -	uvc_dismiss_privileges(handle);
> -	v4l2_fh_del(&handle->vfh);
> -	v4l2_fh_exit(&handle->vfh);
> -	kfree(handle);
> +	vb2_fop_release(file);
>  	file->private_data = NULL;
>  
>  	return 0;
> @@ -753,91 +677,6 @@ static int uvc_ioctl_try_fmt(struct file *file, void *fh,
>  	return uvc_v4l2_try_format(stream, fmt, &probe, NULL, NULL);
>  }
>  
> -static int uvc_ioctl_reqbufs(struct file *file, void *fh,
> -			     struct v4l2_requestbuffers *rb)
> -{
> -	struct uvc_fh *handle = fh;
> -	struct uvc_streaming *stream = handle->stream;
> -	int ret;
> -
> -	ret = uvc_acquire_privileges(handle);
> -	if (ret < 0)
> -		return ret;
> -
> -	mutex_lock(&stream->mutex);
> -	ret = uvc_request_buffers(&stream->queue, rb);
> -	mutex_unlock(&stream->mutex);
> -	if (ret < 0)
> -		return ret;
> -
> -	if (ret == 0)
> -		uvc_dismiss_privileges(handle);
> -
> -	return 0;
> -}
> -
> -static int uvc_ioctl_querybuf(struct file *file, void *fh,
> -			      struct v4l2_buffer *buf)
> -{
> -	struct uvc_fh *handle = fh;
> -	struct uvc_streaming *stream = handle->stream;
> -
> -	if (!uvc_has_privileges(handle))
> -		return -EBUSY;
> -
> -	return uvc_query_buffer(&stream->queue, buf);
> -}
> -
> -static int uvc_ioctl_qbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
> -{
> -	struct uvc_fh *handle = fh;
> -	struct uvc_streaming *stream = handle->stream;
> -
> -	if (!uvc_has_privileges(handle))
> -		return -EBUSY;
> -
> -	return uvc_queue_buffer(&stream->queue,
> -				stream->vdev.v4l2_dev->mdev, buf);
> -}
> -
> -static int uvc_ioctl_expbuf(struct file *file, void *fh,
> -			    struct v4l2_exportbuffer *exp)
> -{
> -	struct uvc_fh *handle = fh;
> -	struct uvc_streaming *stream = handle->stream;
> -
> -	if (!uvc_has_privileges(handle))
> -		return -EBUSY;
> -
> -	return uvc_export_buffer(&stream->queue, exp);
> -}
> -
> -static int uvc_ioctl_dqbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
> -{
> -	struct uvc_fh *handle = fh;
> -	struct uvc_streaming *stream = handle->stream;
> -
> -	if (!uvc_has_privileges(handle))
> -		return -EBUSY;
> -
> -	return uvc_dequeue_buffer(&stream->queue, buf,
> -				  file->f_flags & O_NONBLOCK);
> -}
> -
> -static int uvc_ioctl_create_bufs(struct file *file, void *fh,
> -				  struct v4l2_create_buffers *cb)
> -{
> -	struct uvc_fh *handle = fh;
> -	struct uvc_streaming *stream = handle->stream;
> -	int ret;
> -
> -	ret = uvc_acquire_privileges(handle);
> -	if (ret < 0)
> -		return ret;
> -
> -	return uvc_create_buffers(&stream->queue, cb);
> -}
> -
>  static int uvc_ioctl_streamon(struct file *file, void *fh,
>  			      enum v4l2_buf_type type)
>  {
> @@ -845,11 +684,6 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
>  	struct uvc_streaming *stream = handle->stream;
>  	int ret;
>  
> -	if (!uvc_has_privileges(handle))
> -		return -EBUSY;
> -
> -	guard(mutex)(&stream->mutex);
> -
>  	if (handle->is_streaming)
>  		return 0;
>  
> @@ -857,7 +691,7 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
>  	if (ret)
>  		return ret;
>  
> -	ret = uvc_queue_streamon(&stream->queue, type);
> +	ret = vb2_ioctl_streamon(file, fh, type);
>  	if (ret) {
>  		uvc_pm_put(stream->dev);
>  		return ret;
> @@ -873,13 +707,12 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
>  {
>  	struct uvc_fh *handle = fh;
>  	struct uvc_streaming *stream = handle->stream;
> +	int ret;
>  
> -	if (!uvc_has_privileges(handle))
> -		return -EBUSY;
> -
> -	guard(mutex)(&stream->mutex);
> +	ret = vb2_ioctl_streamoff(file, fh, type);
> +	if (ret)
> +		return ret;
>  
> -	uvc_queue_streamoff(&stream->queue, type);
>  	if (handle->is_streaming) {
>  		handle->is_streaming = false;
>  		uvc_pm_put(stream->dev);
> @@ -962,13 +795,13 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
>  static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
>  {
>  	struct uvc_fh *handle = fh;
> +	struct uvc_streaming *stream = handle->stream;
>  	struct uvc_video_chain *chain = handle->chain;
>  	u8 *buf;
>  	int ret;
>  
> -	ret = uvc_acquire_privileges(handle);
> -	if (ret < 0)
> -		return ret;
> +	if (vb2_is_busy(&stream->queue.queue))
> +		return -EBUSY;
>  
>  	if (chain->selector == NULL ||
>  	    (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
> @@ -1471,50 +1304,6 @@ static long uvc_v4l2_unlocked_ioctl(struct file *file,
>  	return ret;
>  }
>  
> -static ssize_t uvc_v4l2_read(struct file *file, char __user *data,
> -		    size_t count, loff_t *ppos)
> -{
> -	struct uvc_fh *handle = file->private_data;
> -	struct uvc_streaming *stream = handle->stream;
> -
> -	uvc_dbg(stream->dev, CALLS, "%s: not implemented\n", __func__);
> -	return -EINVAL;
> -}
> -
> -static int uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
> -{
> -	struct uvc_fh *handle = file->private_data;
> -	struct uvc_streaming *stream = handle->stream;
> -
> -	uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
> -
> -	return uvc_queue_mmap(&stream->queue, vma);
> -}
> -
> -static __poll_t uvc_v4l2_poll(struct file *file, poll_table *wait)
> -{
> -	struct uvc_fh *handle = file->private_data;
> -	struct uvc_streaming *stream = handle->stream;
> -
> -	uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
> -
> -	return uvc_queue_poll(&stream->queue, file, wait);
> -}
> -
> -#ifndef CONFIG_MMU
> -static unsigned long uvc_v4l2_get_unmapped_area(struct file *file,
> -		unsigned long addr, unsigned long len, unsigned long pgoff,
> -		unsigned long flags)
> -{
> -	struct uvc_fh *handle = file->private_data;
> -	struct uvc_streaming *stream = handle->stream;
> -
> -	uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
> -
> -	return uvc_queue_get_unmapped_area(&stream->queue, pgoff);
> -}
> -#endif
> -
>  const struct v4l2_ioctl_ops uvc_ioctl_ops = {
>  	.vidioc_g_fmt_vid_cap = uvc_ioctl_g_fmt,
>  	.vidioc_g_fmt_vid_out = uvc_ioctl_g_fmt,
> @@ -1527,12 +1316,13 @@ const struct v4l2_ioctl_ops uvc_ioctl_ops = {
>  	.vidioc_enum_fmt_vid_out = uvc_ioctl_enum_fmt,
>  	.vidioc_try_fmt_vid_cap = uvc_ioctl_try_fmt,
>  	.vidioc_try_fmt_vid_out = uvc_ioctl_try_fmt,
> -	.vidioc_reqbufs = uvc_ioctl_reqbufs,
> -	.vidioc_querybuf = uvc_ioctl_querybuf,
> -	.vidioc_qbuf = uvc_ioctl_qbuf,
> -	.vidioc_expbuf = uvc_ioctl_expbuf,
> -	.vidioc_dqbuf = uvc_ioctl_dqbuf,
> -	.vidioc_create_bufs = uvc_ioctl_create_bufs,
> +	.vidioc_reqbufs = vb2_ioctl_reqbufs,
> +	.vidioc_querybuf = vb2_ioctl_querybuf,
> +	.vidioc_prepare_buf = vb2_ioctl_prepare_buf,
> +	.vidioc_qbuf = vb2_ioctl_qbuf,
> +	.vidioc_expbuf = vb2_ioctl_expbuf,
> +	.vidioc_dqbuf = vb2_ioctl_dqbuf,
> +	.vidioc_create_bufs = vb2_ioctl_create_bufs,
>  	.vidioc_streamon = uvc_ioctl_streamon,
>  	.vidioc_streamoff = uvc_ioctl_streamoff,
>  	.vidioc_enum_input = uvc_ioctl_enum_input,
> @@ -1559,11 +1349,10 @@ const struct v4l2_file_operations uvc_fops = {
>  #ifdef CONFIG_COMPAT
>  	.compat_ioctl32	= uvc_v4l2_compat_ioctl32,
>  #endif
> -	.read		= uvc_v4l2_read,
> -	.mmap		= uvc_v4l2_mmap,
> -	.poll		= uvc_v4l2_poll,
> +	.mmap		= vb2_fop_mmap,
> +	.poll		= vb2_fop_poll,
>  #ifndef CONFIG_MMU
> -	.get_unmapped_area = uvc_v4l2_get_unmapped_area,
> +	.get_unmapped_area = vb2_fop_get_unmapped_area,
>  #endif
>  };
>  
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index b9f8eb62ba1d82ea7788cf6c10cc838a429dbc9e..3ddbf065a2cbae40ee48cb06f84ca8f0052990c4 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -326,7 +326,10 @@ struct uvc_buffer {
>  
>  struct uvc_video_queue {
>  	struct vb2_queue queue;
> -	struct mutex mutex;			/* Protects queue */
> +	struct mutex mutex;			/*
> +						 * Serializes vb2_queue and
> +						 * fops
> +						 */
>  
>  	unsigned int flags;
>  	unsigned int buf_used;
> @@ -349,7 +352,6 @@ struct uvc_video_chain {
>  						 * uvc_fh.pending_async_ctrls
>  						 */
>  
> -	struct v4l2_prio_state prio;		/* V4L2 priority state */
>  	u32 caps;				/* V4L2 chain-wide caps */
>  	u8 ctrl_class_bitmap;			/* Bitmap of valid classes */
>  };
> @@ -619,16 +621,10 @@ struct uvc_device {
>  	struct uvc_entity *gpio_unit;
>  };
>  
> -enum uvc_handle_state {
> -	UVC_HANDLE_PASSIVE	= 0,
> -	UVC_HANDLE_ACTIVE	= 1,
> -};
> -
>  struct uvc_fh {
>  	struct v4l2_fh vfh;
>  	struct uvc_video_chain *chain;
>  	struct uvc_streaming *stream;
> -	enum uvc_handle_state state;
>  	unsigned int pending_async_ctrls;
>  	bool is_streaming;
>  };
> @@ -687,36 +683,11 @@ struct uvc_entity *uvc_entity_by_id(struct uvc_device *dev, int id);
>  
>  /* Video buffers queue management. */
>  int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type);
> -void uvc_queue_release(struct uvc_video_queue *queue);
> -int uvc_request_buffers(struct uvc_video_queue *queue,
> -			struct v4l2_requestbuffers *rb);
> -int uvc_query_buffer(struct uvc_video_queue *queue,
> -		     struct v4l2_buffer *v4l2_buf);
> -int uvc_create_buffers(struct uvc_video_queue *queue,
> -		       struct v4l2_create_buffers *v4l2_cb);
> -int uvc_queue_buffer(struct uvc_video_queue *queue,
> -		     struct media_device *mdev,
> -		     struct v4l2_buffer *v4l2_buf);
> -int uvc_export_buffer(struct uvc_video_queue *queue,
> -		      struct v4l2_exportbuffer *exp);
> -int uvc_dequeue_buffer(struct uvc_video_queue *queue,
> -		       struct v4l2_buffer *v4l2_buf, int nonblocking);
> -int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type);
> -int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type);
>  void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect);
>  struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
>  					 struct uvc_buffer *buf);
>  struct uvc_buffer *uvc_queue_get_current_buffer(struct uvc_video_queue *queue);
>  void uvc_queue_buffer_release(struct uvc_buffer *buf);
> -int uvc_queue_mmap(struct uvc_video_queue *queue,
> -		   struct vm_area_struct *vma);
> -__poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
> -			poll_table *wait);
> -#ifndef CONFIG_MMU
> -unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
> -					  unsigned long pgoff);
> -#endif
> -int uvc_queue_allocated(struct uvc_video_queue *queue);
>  static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
>  {
>  	return vb2_is_streaming(&queue->queue);
> 

Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>

Regards,

	Hans

Re: [PATCH 3/3] media: uvcvideo: Remove stream->is_streaming field

[Hans Verkuil]

On 22/05/2025 19:58, Ricardo Ribalda wrote:
> The is_streaming field is used by modular PM to know if the device is
> currently streaming or not.
> 
> With the transition to vb2 and fop helpers, we can use vb2 functions for
> the same functionality.
> 
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
>  drivers/media/usb/uvc/uvc_v4l2.c | 12 +++++-------
>  drivers/media/usb/uvc/uvcvideo.h |  1 -
>  2 files changed, 5 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> index 7a5ecbefa32c0a6b74c85d7f77a25b433598471e..51419f443f2c43dfd17a9782352bd2cde1094732 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -617,7 +617,8 @@ static int uvc_v4l2_release(struct file *file)
>  
>  	uvc_ctrl_cleanup_fh(handle);
>  
> -	if (handle->is_streaming)
> +	if (stream->queue.queue.owner == file->private_data &&

Use vb2_queue_is_busy(&stream->queue) instead of directly accessing the owner field.
But see below, since this can be dropped altogether.

> +	    uvc_queue_streaming(&stream->queue))
>  		uvc_pm_put(stream->dev);

I think patch 1/3 can be improved, which likely makes this patch obsolete.

The uvc_pm_get/put should be placed in the start/stop_streaming callbacks. That's
where you need them, and it avoids all these is_streaming tests. And it allows you to
use the vb2_ioctl_streamon/off helpers in patch 2, since the streamon/off functions
no longer mess with the uvc_pm_get/put functions.

Regards,

	Hans

>  
>  	/* Release the file handle. */
> @@ -684,7 +685,7 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
>  	struct uvc_streaming *stream = handle->stream;
>  	int ret;
>  
> -	if (handle->is_streaming)
> +	if (uvc_queue_streaming(&stream->queue))
>  		return 0;
>  
>  	ret = uvc_pm_get(stream->dev);
> @@ -697,8 +698,6 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
>  		return ret;
>  	}
>  
> -	handle->is_streaming = true;
> -
>  	return 0;
>  }
>  
> @@ -707,16 +706,15 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
>  {
>  	struct uvc_fh *handle = fh;
>  	struct uvc_streaming *stream = handle->stream;
> +	bool was_streaming = uvc_queue_streaming(&stream->queue);
>  	int ret;
>  
>  	ret = vb2_ioctl_streamoff(file, fh, type);
>  	if (ret)
>  		return ret;
>  
> -	if (handle->is_streaming) {
> -		handle->is_streaming = false;
> +	if (was_streaming)
>  		uvc_pm_put(stream->dev);
> -	}
>  
>  	return 0;
>  }
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index 3ddbf065a2cbae40ee48cb06f84ca8f0052990c4..f895f690f7cdc1af942d5f3a5f10e9dd1c956a35 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -626,7 +626,6 @@ struct uvc_fh {
>  	struct uvc_video_chain *chain;
>  	struct uvc_streaming *stream;
>  	unsigned int pending_async_ctrls;
> -	bool is_streaming;
>  };
>  
>  /* ------------------------------------------------------------------------
> 

Re: [PATCH 3/3] media: uvcvideo: Remove stream->is_streaming field

[Ricardo Ribalda]

Hi Hans

On Mon, 2 Jun 2025 at 09:57, Hans Verkuil <hverkuil@xs4all.nl> wrote:
>
> On 22/05/2025 19:58, Ricardo Ribalda wrote:
> > The is_streaming field is used by modular PM to know if the device is
> > currently streaming or not.
> >
> > With the transition to vb2 and fop helpers, we can use vb2 functions for
> > the same functionality.
> >
> > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> > ---
> >  drivers/media/usb/uvc/uvc_v4l2.c | 12 +++++-------
> >  drivers/media/usb/uvc/uvcvideo.h |  1 -
> >  2 files changed, 5 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> > index 7a5ecbefa32c0a6b74c85d7f77a25b433598471e..51419f443f2c43dfd17a9782352bd2cde1094732 100644
> > --- a/drivers/media/usb/uvc/uvc_v4l2.c
> > +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> > @@ -617,7 +617,8 @@ static int uvc_v4l2_release(struct file *file)
> >
> >       uvc_ctrl_cleanup_fh(handle);
> >
> > -     if (handle->is_streaming)
> > +     if (stream->queue.queue.owner == file->private_data &&
>
> Use vb2_queue_is_busy(&stream->queue) instead of directly accessing the owner field.
> But see below, since this can be dropped altogether.
>
> > +         uvc_queue_streaming(&stream->queue))
> >               uvc_pm_put(stream->dev);
>
> I think patch 1/3 can be improved, which likely makes this patch obsolete.

If it is ok with you, I'd rather not touch 1/3. It has landed already
in the uvc tree.

I am reimplemeing 3/3 using  vb2's start_streaming stop_streaming.

BTW, I see that vb2 keeps track of the streaming state, so most of the
code is gone :)


>
> The uvc_pm_get/put should be placed in the start/stop_streaming callbacks. That's
> where you need them, and it avoids all these is_streaming tests. And it allows you to
> use the vb2_ioctl_streamon/off helpers in patch 2, since the streamon/off functions
> no longer mess with the uvc_pm_get/put functions.
>
> Regards,
>
>         Hans
>
> >
> >       /* Release the file handle. */
> > @@ -684,7 +685,7 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
> >       struct uvc_streaming *stream = handle->stream;
> >       int ret;
> >
> > -     if (handle->is_streaming)
> > +     if (uvc_queue_streaming(&stream->queue))
> >               return 0;
> >
> >       ret = uvc_pm_get(stream->dev);
> > @@ -697,8 +698,6 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
> >               return ret;
> >       }
> >
> > -     handle->is_streaming = true;
> > -
> >       return 0;
> >  }
> >
> > @@ -707,16 +706,15 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
> >  {
> >       struct uvc_fh *handle = fh;
> >       struct uvc_streaming *stream = handle->stream;
> > +     bool was_streaming = uvc_queue_streaming(&stream->queue);
> >       int ret;
> >
> >       ret = vb2_ioctl_streamoff(file, fh, type);
> >       if (ret)
> >               return ret;
> >
> > -     if (handle->is_streaming) {
> > -             handle->is_streaming = false;
> > +     if (was_streaming)
> >               uvc_pm_put(stream->dev);
> > -     }
> >
> >       return 0;
> >  }
> > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> > index 3ddbf065a2cbae40ee48cb06f84ca8f0052990c4..f895f690f7cdc1af942d5f3a5f10e9dd1c956a35 100644
> > --- a/drivers/media/usb/uvc/uvcvideo.h
> > +++ b/drivers/media/usb/uvc/uvcvideo.h
> > @@ -626,7 +626,6 @@ struct uvc_fh {
> >       struct uvc_video_chain *chain;
> >       struct uvc_streaming *stream;
> >       unsigned int pending_async_ctrls;
> > -     bool is_streaming;
> >  };
> >
> >  /* ------------------------------------------------------------------------
> >
>


-- 
Ricardo Ribalda