[PATCH v3 0/5] media: uvcvideo: use vb2 ioctl and fop helpers

[PATCH v3 0/5] 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 patch:
media: uvcvideo: Refactor uvc_queue_streamon
Is already in the uvc tree. It is here just for CI purposes, do not
review.

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>
---
Changes in v3:
- Refactor start/stop_streaming(): make meta and video versions
- Link to v2: https://lore.kernel.org/r/20250602-uvc-fop-v2-0-508a293eae81@chromium.org

Changes in v2, Thanks HansV:
- Fix typos
- Use start_streaming and stop_streaming for managing pm
- Link to v1: https://lore.kernel.org/r/20250522-uvc-fop-v1-0-3bfe7a00f31d@chromium.org

---
Hans Verkuil (1):
      media: uvcvideo: Use vb2 ioctl and fop helpers

Ricardo Ribalda (4):
      media: uvcvideo: Refactor uvc_queue_streamon
      media: uvcvideo: Handle locks in uvc_queue_return_buffers
      media: uvcvideo: Split uvc_stop_streaming()
      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    | 194 +++++------------------
 drivers/media/usb/uvc/uvc_v4l2.c     | 291 ++---------------------------------
 drivers/media/usb/uvc/uvcvideo.h     |  38 +----
 5 files changed, 64 insertions(+), 501 deletions(-)
---
base-commit: 02e8ee21bd40010ab00f4a8e995f4cc97dc83dea
change-id: 20250521-uvc-fop-b74e9007dd51

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

[PATCH v3 1/5] 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 always called after uvc_pm_get,
this change makes the code more resiliant to future changes.

This change also avoids calling streamoff, which is a rather ugly thing
to do.

Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>
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;

-- 
2.49.0.1266.g31b7d2e469-goog

[PATCH v3 2/5] 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
boilerplate code 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 grant exclusive ownership of the device.

Reviewed-by: Hans de Goede <hansg@kernel.org>
Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>
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);

-- 
2.49.0.1266.g31b7d2e469-goog

Re: [PATCH v3 2/5] media: uvcvideo: Use vb2 ioctl and fop helpers

[Hans de Goede]

Hi Ricardo,

On 2-Jun-25 18:06, 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
> boilerplate code 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 grant exclusive ownership of the device.
> 
> Reviewed-by: Hans de Goede <hansg@kernel.org>
> Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>
> 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;
>  }

As Hans V. mentioned in the discussion on v2, the chain->prio related changes
are unrelated to the rest of the changes and these should be dropped (or at
a minimum split out into a separate patch).

Laurent also remarked the following in the v2 discussion wrt the commit msg:

"The driver implements a privilege-management
system similar to the vb2_queue_is_busy() checks in the vb2 ioctl
handlers, as the ioctl handlers didn't exist back then.

Please reword the commit message to make this clearer."

Regards,

Hans


> @@ -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);
> 

[PATCH v3 3/5] media: uvcvideo: Handle locks in uvc_queue_return_buffers

[Ricardo Ribalda]

Most of the calls to uvc_queue_return_buffers() wrap the call with
spin_lock_irq()/spin_unlock_irq().

Rename uvc_queue_return_buffers to __uvc_queue_return_buffers to
indicate that this is the version that does not handle locks and create
a new version of the function that handles the lock.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_queue.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
index 72c5494dee9f46ff61072e7d293bfaddda40e615..8f9737ac729546683ca48f5e71ce3dfacbae2926 100644
--- a/drivers/media/usb/uvc/uvc_queue.c
+++ b/drivers/media/usb/uvc/uvc_queue.c
@@ -42,13 +42,15 @@ static inline struct uvc_buffer *uvc_vbuf_to_buffer(struct vb2_v4l2_buffer *buf)
  *
  * This function must be called with the queue spinlock held.
  */
-static void uvc_queue_return_buffers(struct uvc_video_queue *queue,
-			       enum uvc_buffer_state state)
+static void __uvc_queue_return_buffers(struct uvc_video_queue *queue,
+				       enum uvc_buffer_state state)
 {
 	enum vb2_buffer_state vb2_state = state == UVC_BUF_STATE_ERROR
 					? VB2_BUF_STATE_ERROR
 					: VB2_BUF_STATE_QUEUED;
 
+	lockdep_assert_held(&queue->irqlock);
+
 	while (!list_empty(&queue->irqqueue)) {
 		struct uvc_buffer *buf = list_first_entry(&queue->irqqueue,
 							  struct uvc_buffer,
@@ -59,6 +61,14 @@ static void uvc_queue_return_buffers(struct uvc_video_queue *queue,
 	}
 }
 
+static void uvc_queue_return_buffers(struct uvc_video_queue *queue,
+				     enum uvc_buffer_state state)
+{
+	spin_lock_irq(&queue->irqlock);
+	__uvc_queue_return_buffers(queue, state);
+	spin_unlock_irq(&queue->irqlock);
+}
+
 /* -----------------------------------------------------------------------------
  * videobuf2 queue operations
  */
@@ -171,9 +181,7 @@ static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
 	if (ret == 0)
 		return 0;
 
-	spin_lock_irq(&queue->irqlock);
 	uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED);
-	spin_unlock_irq(&queue->irqlock);
 
 	return ret;
 }
@@ -187,9 +195,7 @@ static void uvc_stop_streaming(struct vb2_queue *vq)
 	if (vq->type != V4L2_BUF_TYPE_META_CAPTURE)
 		uvc_video_stop_streaming(uvc_queue_to_stream(queue));
 
-	spin_lock_irq(&queue->irqlock);
 	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
-	spin_unlock_irq(&queue->irqlock);
 }
 
 static const struct vb2_ops uvc_queue_qops = {
@@ -263,7 +269,7 @@ void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect)
 	unsigned long flags;
 
 	spin_lock_irqsave(&queue->irqlock, flags);
-	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
+	__uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
 	/*
 	 * This must be protected by the irqlock spinlock to avoid race
 	 * conditions between uvc_buffer_queue and the disconnection event that

-- 
2.49.0.1266.g31b7d2e469-goog

Re: [PATCH v3 3/5] media: uvcvideo: Handle locks in uvc_queue_return_buffers

[Hans de Goede]

Hi Ricardo,

On 2-Jun-25 18:06, Ricardo Ribalda wrote:
> Most of the calls to uvc_queue_return_buffers() wrap the call with
> spin_lock_irq()/spin_unlock_irq().
> 
> Rename uvc_queue_return_buffers to __uvc_queue_return_buffers to
> indicate that this is the version that does not handle locks and create
> a new version of the function that handles the lock.
> 
> 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_queue.c | 20 +++++++++++++-------
>  1 file changed, 13 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
> index 72c5494dee9f46ff61072e7d293bfaddda40e615..8f9737ac729546683ca48f5e71ce3dfacbae2926 100644
> --- a/drivers/media/usb/uvc/uvc_queue.c
> +++ b/drivers/media/usb/uvc/uvc_queue.c
> @@ -42,13 +42,15 @@ static inline struct uvc_buffer *uvc_vbuf_to_buffer(struct vb2_v4l2_buffer *buf)
>   *
>   * This function must be called with the queue spinlock held.
>   */
> -static void uvc_queue_return_buffers(struct uvc_video_queue *queue,
> -			       enum uvc_buffer_state state)
> +static void __uvc_queue_return_buffers(struct uvc_video_queue *queue,
> +				       enum uvc_buffer_state state)
>  {
>  	enum vb2_buffer_state vb2_state = state == UVC_BUF_STATE_ERROR
>  					? VB2_BUF_STATE_ERROR
>  					: VB2_BUF_STATE_QUEUED;
>  
> +	lockdep_assert_held(&queue->irqlock);
> +
>  	while (!list_empty(&queue->irqqueue)) {
>  		struct uvc_buffer *buf = list_first_entry(&queue->irqqueue,
>  							  struct uvc_buffer,
> @@ -59,6 +61,14 @@ static void uvc_queue_return_buffers(struct uvc_video_queue *queue,
>  	}
>  }
>  
> +static void uvc_queue_return_buffers(struct uvc_video_queue *queue,
> +				     enum uvc_buffer_state state)
> +{
> +	spin_lock_irq(&queue->irqlock);
> +	__uvc_queue_return_buffers(queue, state);
> +	spin_unlock_irq(&queue->irqlock);
> +}
> +
>  /* -----------------------------------------------------------------------------
>   * videobuf2 queue operations
>   */
> @@ -171,9 +181,7 @@ static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	if (ret == 0)
>  		return 0;
>  
> -	spin_lock_irq(&queue->irqlock);
>  	uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED);
> -	spin_unlock_irq(&queue->irqlock);
>  
>  	return ret;
>  }
> @@ -187,9 +195,7 @@ static void uvc_stop_streaming(struct vb2_queue *vq)
>  	if (vq->type != V4L2_BUF_TYPE_META_CAPTURE)
>  		uvc_video_stop_streaming(uvc_queue_to_stream(queue));
>  
> -	spin_lock_irq(&queue->irqlock);
>  	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
> -	spin_unlock_irq(&queue->irqlock);
>  }
>  
>  static const struct vb2_ops uvc_queue_qops = {
> @@ -263,7 +269,7 @@ void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect)
>  	unsigned long flags;
>  
>  	spin_lock_irqsave(&queue->irqlock, flags);
> -	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
> +	__uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
>  	/*
>  	 * This must be protected by the irqlock spinlock to avoid race
>  	 * conditions between uvc_buffer_queue and the disconnection event that
> 

[PATCH v3 4/5] media: uvcvideo: Split uvc_stop_streaming()

[Ricardo Ribalda]

uvc_stop_streaming() is used for meta and video nodes. Split the function
in two to avoid confusion.

Use this opportunity to rename uvc_start_streaming() to
uvc_start_streaming_video(), as it is only called by the video nodes.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_queue.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
index 8f9737ac729546683ca48f5e71ce3dfacbae2926..3f357c2d48cfd258c26f0342007d1d12f1e01007 100644
--- a/drivers/media/usb/uvc/uvc_queue.c
+++ b/drivers/media/usb/uvc/uvc_queue.c
@@ -167,7 +167,7 @@ static void uvc_buffer_finish(struct vb2_buffer *vb)
 		uvc_video_clock_update(stream, vbuf, buf);
 }
 
-static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
+static int uvc_start_streaming_video(struct vb2_queue *vq, unsigned int count)
 {
 	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
 	struct uvc_streaming *stream = uvc_queue_to_stream(queue);
@@ -186,14 +186,22 @@ static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
 	return ret;
 }
 
-static void uvc_stop_streaming(struct vb2_queue *vq)
+static void uvc_stop_streaming_video(struct vb2_queue *vq)
 {
 	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
 
 	lockdep_assert_irqs_enabled();
 
-	if (vq->type != V4L2_BUF_TYPE_META_CAPTURE)
-		uvc_video_stop_streaming(uvc_queue_to_stream(queue));
+	uvc_video_stop_streaming(uvc_queue_to_stream(queue));
+
+	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
+}
+
+static void uvc_stop_streaming_meta(struct vb2_queue *vq)
+{
+	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
+
+	lockdep_assert_irqs_enabled();
 
 	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
 }
@@ -203,15 +211,15 @@ static const struct vb2_ops uvc_queue_qops = {
 	.buf_prepare = uvc_buffer_prepare,
 	.buf_queue = uvc_buffer_queue,
 	.buf_finish = uvc_buffer_finish,
-	.start_streaming = uvc_start_streaming,
-	.stop_streaming = uvc_stop_streaming,
+	.start_streaming = uvc_start_streaming_video,
+	.stop_streaming = uvc_stop_streaming_video,
 };
 
 static const struct vb2_ops uvc_meta_queue_qops = {
 	.queue_setup = uvc_queue_setup,
 	.buf_prepare = uvc_buffer_prepare,
 	.buf_queue = uvc_buffer_queue,
-	.stop_streaming = uvc_stop_streaming,
+	.stop_streaming = uvc_stop_streaming_meta,
 };
 
 int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type)

-- 
2.49.0.1266.g31b7d2e469-goog

Re: [PATCH v3 4/5] media: uvcvideo: Split uvc_stop_streaming()

[Hans de Goede]

Hi Ricardo,

On 2-Jun-25 18:06, Ricardo Ribalda wrote:
> uvc_stop_streaming() is used for meta and video nodes. Split the function
> in two to avoid confusion.
> 
> Use this opportunity to rename uvc_start_streaming() to
> uvc_start_streaming_video(), as it is only called by the video nodes.
> 
> 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_queue.c | 22 +++++++++++++++-------
>  1 file changed, 15 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
> index 8f9737ac729546683ca48f5e71ce3dfacbae2926..3f357c2d48cfd258c26f0342007d1d12f1e01007 100644
> --- a/drivers/media/usb/uvc/uvc_queue.c
> +++ b/drivers/media/usb/uvc/uvc_queue.c
> @@ -167,7 +167,7 @@ static void uvc_buffer_finish(struct vb2_buffer *vb)
>  		uvc_video_clock_update(stream, vbuf, buf);
>  }
>  
> -static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
> +static int uvc_start_streaming_video(struct vb2_queue *vq, unsigned int count)
>  {
>  	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
>  	struct uvc_streaming *stream = uvc_queue_to_stream(queue);
> @@ -186,14 +186,22 @@ static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	return ret;
>  }
>  
> -static void uvc_stop_streaming(struct vb2_queue *vq)
> +static void uvc_stop_streaming_video(struct vb2_queue *vq)
>  {
>  	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
>  
>  	lockdep_assert_irqs_enabled();
>  
> -	if (vq->type != V4L2_BUF_TYPE_META_CAPTURE)
> -		uvc_video_stop_streaming(uvc_queue_to_stream(queue));
> +	uvc_video_stop_streaming(uvc_queue_to_stream(queue));
> +
> +	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
> +}
> +
> +static void uvc_stop_streaming_meta(struct vb2_queue *vq)
> +{
> +	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
> +
> +	lockdep_assert_irqs_enabled();
>  
>  	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
>  }
> @@ -203,15 +211,15 @@ static const struct vb2_ops uvc_queue_qops = {
>  	.buf_prepare = uvc_buffer_prepare,
>  	.buf_queue = uvc_buffer_queue,
>  	.buf_finish = uvc_buffer_finish,
> -	.start_streaming = uvc_start_streaming,
> -	.stop_streaming = uvc_stop_streaming,
> +	.start_streaming = uvc_start_streaming_video,
> +	.stop_streaming = uvc_stop_streaming_video,
>  };
>  
>  static const struct vb2_ops uvc_meta_queue_qops = {
>  	.queue_setup = uvc_queue_setup,
>  	.buf_prepare = uvc_buffer_prepare,
>  	.buf_queue = uvc_buffer_queue,
> -	.stop_streaming = uvc_stop_streaming,
> +	.stop_streaming = uvc_stop_streaming_meta,
>  };
>  
>  int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type)
> 

[PATCH v3 5/5] 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. The great benefit is that vb2 already takes
track of the streaming state for us.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_queue.c |  9 +++++++
 drivers/media/usb/uvc/uvc_v4l2.c  | 51 ++-------------------------------------
 drivers/media/usb/uvc/uvcvideo.h  |  1 -
 3 files changed, 11 insertions(+), 50 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
index 3f357c2d48cfd258c26f0342007d1d12f1e01007..6e845705b3286348a60650eb262e620dc6039d60 100644
--- a/drivers/media/usb/uvc/uvc_queue.c
+++ b/drivers/media/usb/uvc/uvc_queue.c
@@ -175,12 +175,18 @@ static int uvc_start_streaming_video(struct vb2_queue *vq, unsigned int count)
 
 	lockdep_assert_irqs_enabled();
 
+	ret = uvc_pm_get(stream->dev);
+	if (ret)
+		return ret;
+
 	queue->buf_used = 0;
 
 	ret = uvc_video_start_streaming(stream);
 	if (ret == 0)
 		return 0;
 
+	uvc_pm_put(stream->dev);
+
 	uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED);
 
 	return ret;
@@ -189,11 +195,14 @@ static int uvc_start_streaming_video(struct vb2_queue *vq, unsigned int count)
 static void uvc_stop_streaming_video(struct vb2_queue *vq)
 {
 	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
+	struct uvc_streaming *stream = uvc_queue_to_stream(queue);
 
 	lockdep_assert_irqs_enabled();
 
 	uvc_video_stop_streaming(uvc_queue_to_stream(queue));
 
+	uvc_pm_put(stream->dev);
+
 	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
 }
 
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 7a5ecbefa32c0a6b74c85d7f77a25b433598471e..d4bee0d4334b764c0cf02363b573b55fb44eb228 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -617,9 +617,6 @@ static int uvc_v4l2_release(struct file *file)
 
 	uvc_ctrl_cleanup_fh(handle);
 
-	if (handle->is_streaming)
-		uvc_pm_put(stream->dev);
-
 	/* Release the file handle. */
 	vb2_fop_release(file);
 	file->private_data = NULL;
@@ -677,50 +674,6 @@ 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_streamon(struct file *file, void *fh,
-			      enum v4l2_buf_type type)
-{
-	struct uvc_fh *handle = fh;
-	struct uvc_streaming *stream = handle->stream;
-	int ret;
-
-	if (handle->is_streaming)
-		return 0;
-
-	ret = uvc_pm_get(stream->dev);
-	if (ret)
-		return ret;
-
-	ret = vb2_ioctl_streamon(file, fh, type);
-	if (ret) {
-		uvc_pm_put(stream->dev);
-		return ret;
-	}
-
-	handle->is_streaming = true;
-
-	return 0;
-}
-
-static int uvc_ioctl_streamoff(struct file *file, void *fh,
-			       enum v4l2_buf_type type)
-{
-	struct uvc_fh *handle = fh;
-	struct uvc_streaming *stream = handle->stream;
-	int ret;
-
-	ret = vb2_ioctl_streamoff(file, fh, type);
-	if (ret)
-		return ret;
-
-	if (handle->is_streaming) {
-		handle->is_streaming = false;
-		uvc_pm_put(stream->dev);
-	}
-
-	return 0;
-}
-
 static int uvc_ioctl_enum_input(struct file *file, void *fh,
 				struct v4l2_input *input)
 {
@@ -1323,8 +1276,8 @@ const struct v4l2_ioctl_ops uvc_ioctl_ops = {
 	.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_streamon = vb2_ioctl_streamon,
+	.vidioc_streamoff = vb2_ioctl_streamoff,
 	.vidioc_enum_input = uvc_ioctl_enum_input,
 	.vidioc_g_input = uvc_ioctl_g_input,
 	.vidioc_s_input = uvc_ioctl_s_input,
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;
 };
 
 /* ------------------------------------------------------------------------

-- 
2.49.0.1266.g31b7d2e469-goog

Re: [PATCH v3 5/5] media: uvcvideo: Remove stream->is_streaming field

[Hans de Goede]

Hi Ricardo,

On 2-Jun-25 18:06, 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. The great benefit is that vb2 already takes
> track of the streaming state for us.
> 
> 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_queue.c |  9 +++++++
>  drivers/media/usb/uvc/uvc_v4l2.c  | 51 ++-------------------------------------
>  drivers/media/usb/uvc/uvcvideo.h  |  1 -
>  3 files changed, 11 insertions(+), 50 deletions(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
> index 3f357c2d48cfd258c26f0342007d1d12f1e01007..6e845705b3286348a60650eb262e620dc6039d60 100644
> --- a/drivers/media/usb/uvc/uvc_queue.c
> +++ b/drivers/media/usb/uvc/uvc_queue.c
> @@ -175,12 +175,18 @@ static int uvc_start_streaming_video(struct vb2_queue *vq, unsigned int count)
>  
>  	lockdep_assert_irqs_enabled();
>  
> +	ret = uvc_pm_get(stream->dev);
> +	if (ret)
> +		return ret;
> +
>  	queue->buf_used = 0;
>  
>  	ret = uvc_video_start_streaming(stream);
>  	if (ret == 0)
>  		return 0;
>  
> +	uvc_pm_put(stream->dev);
> +
>  	uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED);
>  
>  	return ret;
> @@ -189,11 +195,14 @@ static int uvc_start_streaming_video(struct vb2_queue *vq, unsigned int count)
>  static void uvc_stop_streaming_video(struct vb2_queue *vq)
>  {
>  	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
> +	struct uvc_streaming *stream = uvc_queue_to_stream(queue);
>  
>  	lockdep_assert_irqs_enabled();
>  
>  	uvc_video_stop_streaming(uvc_queue_to_stream(queue));
>  
> +	uvc_pm_put(stream->dev);
> +
>  	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
>  }
>  
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> index 7a5ecbefa32c0a6b74c85d7f77a25b433598471e..d4bee0d4334b764c0cf02363b573b55fb44eb228 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -617,9 +617,6 @@ static int uvc_v4l2_release(struct file *file)
>  
>  	uvc_ctrl_cleanup_fh(handle);
>  
> -	if (handle->is_streaming)
> -		uvc_pm_put(stream->dev);
> -
>  	/* Release the file handle. */
>  	vb2_fop_release(file);
>  	file->private_data = NULL;
> @@ -677,50 +674,6 @@ 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_streamon(struct file *file, void *fh,
> -			      enum v4l2_buf_type type)
> -{
> -	struct uvc_fh *handle = fh;
> -	struct uvc_streaming *stream = handle->stream;
> -	int ret;
> -
> -	if (handle->is_streaming)
> -		return 0;
> -
> -	ret = uvc_pm_get(stream->dev);
> -	if (ret)
> -		return ret;
> -
> -	ret = vb2_ioctl_streamon(file, fh, type);
> -	if (ret) {
> -		uvc_pm_put(stream->dev);
> -		return ret;
> -	}
> -
> -	handle->is_streaming = true;
> -
> -	return 0;
> -}
> -
> -static int uvc_ioctl_streamoff(struct file *file, void *fh,
> -			       enum v4l2_buf_type type)
> -{
> -	struct uvc_fh *handle = fh;
> -	struct uvc_streaming *stream = handle->stream;
> -	int ret;
> -
> -	ret = vb2_ioctl_streamoff(file, fh, type);
> -	if (ret)
> -		return ret;
> -
> -	if (handle->is_streaming) {
> -		handle->is_streaming = false;
> -		uvc_pm_put(stream->dev);
> -	}
> -
> -	return 0;
> -}
> -
>  static int uvc_ioctl_enum_input(struct file *file, void *fh,
>  				struct v4l2_input *input)
>  {
> @@ -1323,8 +1276,8 @@ const struct v4l2_ioctl_ops uvc_ioctl_ops = {
>  	.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_streamon = vb2_ioctl_streamon,
> +	.vidioc_streamoff = vb2_ioctl_streamoff,
>  	.vidioc_enum_input = uvc_ioctl_enum_input,
>  	.vidioc_g_input = uvc_ioctl_g_input,
>  	.vidioc_s_input = uvc_ioctl_s_input,
> 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;
>  };
>  
>  /* ------------------------------------------------------------------------
>