Re: [PATCH v2 2/3] media: uvcvideo: Use vb2 ioctl and fop helpers
From: Ricardo Ribalda
Date: Mon Jun 02 2025 - 15:54:06 EST
Hi Laurent
On Mon, 2 Jun 2025 at 20:31, Laurent Pinchart
<laurent.pinchart@xxxxxxxxxxxxxxxx> wrote:
>
> Hi Ricardo, Hans,
>
> On Mon, Jun 02, 2025 at 12:59:03PM +0000, Ricardo Ribalda wrote:
> > From: Hans Verkuil <hans@xxxxxxxxxxxx>
> >
> > 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
>
> How does it simplify VIDIOC_[GS]_PRIORITY handling ? The only thing this
> patch does related to priority is replace the per-chain priority
> handling with a per-device (as in uvc_device) priority, as the default
> is to use the prio state from v4l2_device. I think this is actually
> incorrect, a UVC device can have multiple independent streaming
> interfaces, so the priority ioctls should no operate on a device-wide
> prio state. Am I missing something ?
You are correct.
The uvcvideo is the only driver that does not use the prio state from
v4l2_device and it makes v4l2-core a bit more complicated.
I have not seen a real use of VIDIOC_[GS]_PRIORITY, so being a bit
incorrect in favor of simplicity is probably a good trade-off.
Anyway it is an easy change to split into a different patch, we can
have the discussion about prio there.
>
> > and allows us
> > to drop the 'privileges' scheme, since that's now handled inside the vb2
> > helpers.
>
> That part is correct. 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. If the prio
> change is also desired, it should be split in a separate patch.
>
> > 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.
>
> There are other changes in behaviour worth noting, some small, some
> quite substantial. Let's start with the small one: .vidioc_querybuf()
> now succeeds when the queue is busy. It seems a check may be missing in
> v4l2-compliance for this.
Agree,
After we land this we can add the check to v4l2-compliance.
>
> The bigger change is related to locking. See below.
>
> > Reviewed-by: Hans de Goede <hansg@xxxxxxxxxx>
> > Reviewed-by: Hans Verkuil <hverkuil@xxxxxxxxx>
> > Signed-off-by: Hans Verkuil <hans@xxxxxxxxxxxx>
> > Co-developed-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
> > Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
> > ---
> > 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;
>
> This will cause the ioctl handlers to use queue->mutex for all ioctls
> (both INFO_FL_QUEUE and !INFO_FL_QUEUE). Locking therefore gets more
> coarse, that should be mentioned in the commit message.
>
> > 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);
>
> This doesn't take any lock anymore. Can that be a problem ?
ack
Probably better to keep the same lock pattern as before. I am adding
mutex_lock/unlock
>
> > 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);
>
> Is this lock still needed ? More broadly speaking, what's the remaining
> purpose of stream->mutex ? Or perhaps the other way around, shouldn't we
> drop queue->mutex, and use stream->mutex everywhere instead ?
Good question, this is the first thing that I tried, and there are
plenty of nested locking that are wrong:
lock(stream->mutex)
lock(stream->muex)
It is probably fixable, but we can do that as a follow-up patch.
>
> >
> > - 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;
>
> You can drop setting private_data to NULL, it's done by
> v4l2_fh_release() called by vb2_fop_release().
ack
>
> >
> > 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);
>
> --
> Regards,
>
> Laurent Pinchart
--
Ricardo Ribalda