Hi Bhupesh,
On Thu, Jan 17, 2013 at 04:23:51PM +0530, Bhupesh Sharma wrote:
> This patch reworks the videobuffer management logic present in the UVC
> webcam gadget and ports it to use the "more apt" videobuf2 framework for
> video buffer management.
>
> To support routing video data captured from a real V4L2 video capture
> device with a "zero copy" operation on videobuffers (as they pass from
> the V4L2 domain to UVC domain via a user-space application), we need to
> support USER_PTR IO method at the UVC gadget side.
>
> So the V4L2 capture device driver can still continue to use MMAP IO
> method and now the user-space application can just pass a pointer to the
> video buffers being dequeued from the V4L2 device side while queueing
> them at the UVC gadget end. This ensures that we have a "zero-copy"
> design as the videobuffers pass from the V4L2 capture device to the UVC
> gadget.
>
> Note that there will still be a need to apply UVC specific payload
> headers on top of each UVC payload data, which will still require a copy
> operation to be performed in the 'encode' routines of the UVC gadget.
>
> This patch also addresses one issue found out while porting the UVC
> gadget to videobuf2 framework:
> - In case the usb requests queued by the gadget get completed
> with a status of -ESHUTDOWN (disconnected from host),
> the queue of videobuf2 should be cancelled to ensure that the
> application space daemon is not left in a state waiting for
> a vb2 to be successfully absorbed at the USB side.
>
> Signed-off-by: Bhupesh Sharma <[email protected]>
> ---
> drivers/usb/gadget/Kconfig | 1 +
> drivers/usb/gadget/uvc_queue.c | 537
> ++++++++++++----------------------------
> drivers/usb/gadget/uvc_queue.h | 25 +--
> drivers/usb/gadget/uvc_v4l2.c | 27 +--
> drivers/usb/gadget/uvc_video.c | 18 +-
> 5 files changed, 189 insertions(+), 419 deletions(-)
>
> diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
> index e0ff51b..b17ee25 100644
> --- a/drivers/usb/gadget/Kconfig
> +++ b/drivers/usb/gadget/Kconfig
> @@ -952,6 +952,7 @@ endif
> config USB_G_WEBCAM
> tristate "USB Webcam Gadget"
> depends on VIDEO_DEV
> + select VIDEOBUF2_VMALLOC
> select USB_LIBCOMPOSITE
> help
> The Webcam Gadget acts as a composite USB Audio and Video Class
> diff --git a/drivers/usb/gadget/uvc_queue.c b/drivers/usb/gadget/uvc_queue.c
> index 104ae9c..bd20fab 100644
> --- a/drivers/usb/gadget/uvc_queue.c
> +++ b/drivers/usb/gadget/uvc_queue.c
> @@ -10,6 +10,7 @@
> * (at your option) any later version.
> */
>
> +#include <linux/atomic.h>
> #include <linux/kernel.h>
> #include <linux/mm.h>
> #include <linux/list.h>
> @@ -18,7 +19,8 @@
> #include <linux/videodev2.h>
> #include <linux/vmalloc.h>
> #include <linux/wait.h>
> -#include <linux/atomic.h>
> +
> +#include <media/videobuf2-vmalloc.h>
>
> #include "uvc.h"
>
> @@ -28,330 +30,169 @@
> * Video queues is initialized by uvc_queue_init(). The function performs
> * basic initialization of the uvc_video_queue struct and never fails.
> *
> - * Video buffer allocation and freeing are performed by uvc_alloc_buffers and
> - * uvc_free_buffers respectively. The former acquires the video queue lock,
> - * while the later must be called with the lock held (so that allocation can
> - * free previously allocated buffers). Trying to free buffers that are mapped
> - * to user space will return -EBUSY.
> - *
> - * Video buffers are managed using two queues. However, unlike most USB video
> - * drivers that use an in queue and an out queue, we use a main queue to hold
> - * all queued buffers (both 'empty' and 'done' buffers), and an irq queue to
> - * hold empty buffers. This design (copied from video-buf) minimizes locking
> - * in interrupt, as only one queue is shared between interrupt and user
> - * contexts.
> - *
> - * Use cases
> - * ---------
> - *
> - * Unless stated otherwise, all operations that modify the irq buffers queue
> - * are protected by the irq spinlock.
> - *
> - * 1. The user queues the buffers, starts streaming and dequeues a buffer.
> - *
> - * The buffers are added to the main and irq queues. Both operations are
> - * protected by the queue lock, and the later is protected by the irq
> - * spinlock as well.
> - *
> - * The completion handler fetches a buffer from the irq queue and fills it
> - * with video data. If no buffer is available (irq queue empty), the
> handler
> - * returns immediately.
> - *
> - * When the buffer is full, the completion handler removes it from the irq
> - * queue, marks it as ready (UVC_BUF_STATE_DONE) and wakes its wait queue.
> - * At that point, any process waiting on the buffer will be woken up. If a
> - * process tries to dequeue a buffer after it has been marked ready, the
> - * dequeing will succeed immediately.
> - *
> - * 2. Buffers are queued, user is waiting on a buffer and the device gets
> - * disconnected.
> - *
> - * When the device is disconnected, the kernel calls the completion
> handler
> - * with an appropriate status code. The handler marks all buffers in the
> - * irq queue as being erroneous (UVC_BUF_STATE_ERROR) and wakes them up so
> - * that any process waiting on a buffer gets woken up.
> - *
> - * Waking up up the first buffer on the irq list is not enough, as the
> - * process waiting on the buffer might restart the dequeue operation
> - * immediately.
> - *
> + * Video buffers are managed by videobuf2. The driver uses a mutex to protect
> + * the videobuf2 queue operations by serializing calls to videobuf2 and a
> + * spinlock to protect the IRQ queue that holds the buffers to be processed
> by
> + * the driver.
> */
>
> -static void
> -uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type)
> -{
> - mutex_init(&queue->mutex);
> - spin_lock_init(&queue->irqlock);
> - INIT_LIST_HEAD(&queue->mainqueue);
> - INIT_LIST_HEAD(&queue->irqqueue);
> - queue->type = type;
> -}
> -
> -/*
> - * Free the video buffers.
> - *
> - * This function must be called with the queue lock held.
> +/*
> -----------------------------------------------------------------------------
> + * videobuf2 queue operations
> */
> -static int uvc_free_buffers(struct uvc_video_queue *queue)
> +
> +static int uvc_queue_setup(struct vb2_queue *vq, const struct v4l2_format
> *fmt,
> + unsigned int *nbuffers, unsigned int *nplanes,
> + unsigned int sizes[], void *alloc_ctxs[])
> {
> - unsigned int i;
> + struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
> + struct uvc_video *video = container_of(queue, struct uvc_video, queue);
>
> - for (i = 0; i < queue->count; ++i) {
> - if (queue->buffer[i].vma_use_count != 0)
> - return -EBUSY;
> - }
> + if (*nbuffers > UVC_MAX_VIDEO_BUFFERS)
> + *nbuffers = UVC_MAX_VIDEO_BUFFERS;
>
> - if (queue->count) {
> - vfree(queue->mem);
> - queue->count = 0;
> - }
> + *nplanes = 1;
> +
> + sizes[0] = video->imagesize;
>
> return 0;
> }
>
> -/*
> - * Allocate the video buffers.
> - *
> - * Pages are reserved to make sure they will not be swapped, as they will be
> - * filled in the URB completion handler.
> - *
> - * Buffers will be individually mapped, so they must all be page aligned.
> - */
> -static int
> -uvc_alloc_buffers(struct uvc_video_queue *queue, unsigned int nbuffers,
> - unsigned int buflength)
> +static int uvc_buffer_prepare(struct vb2_buffer *vb)
> {
> - unsigned int bufsize = PAGE_ALIGN(buflength);
> - unsigned int i;
> - void *mem = NULL;
> - int ret;
> + struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
> + struct uvc_buffer *buf = container_of(vb, struct uvc_buffer, buf);
>
> - if (nbuffers > UVC_MAX_VIDEO_BUFFERS)
> - nbuffers = UVC_MAX_VIDEO_BUFFERS;
> + if (vb->v4l2_buf.type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
> + vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
> + uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
> + return -EINVAL;
> + }
>
> - mutex_lock(&queue->mutex);
> + if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
> + return -ENODEV;
>
> - if ((ret = uvc_free_buffers(queue)) < 0)
> - goto done;
> + buf->state = UVC_BUF_STATE_QUEUED;
> + buf->mem = vb2_plane_vaddr(vb, 0);
> + buf->length = vb2_plane_size(vb, 0);
> + if (vb->v4l2_buf.type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
> + buf->bytesused = 0;
> + else
> + buf->bytesused = vb2_get_plane_payload(vb, 0);
>
> - /* Bail out if no buffers should be allocated. */
> - if (nbuffers == 0)
> - goto done;
> + return 0;
> +}
>
> - /* Decrement the number of buffers until allocation succeeds. */
> - for (; nbuffers > 0; --nbuffers) {
> - mem = vmalloc_32(nbuffers * bufsize);
> - if (mem != NULL)
> - break;
> - }
> +static void uvc_buffer_queue(struct vb2_buffer *vb)
> +{
> + struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
> + struct uvc_buffer *buf = container_of(vb, struct uvc_buffer, buf);
> + unsigned long flags;
>
> - if (mem == NULL) {
> - ret = -ENOMEM;
> - goto done;
> - }
> + spin_lock_irqsave(&queue->irqlock, flags);
>
> - for (i = 0; i < nbuffers; ++i) {
> - memset(&queue->buffer[i], 0, sizeof queue->buffer[i]);
> - queue->buffer[i].buf.index = i;
> - queue->buffer[i].buf.m.offset = i * bufsize;
> - queue->buffer[i].buf.length = buflength;
> - queue->buffer[i].buf.type = queue->type;
> - queue->buffer[i].buf.sequence = 0;
> - queue->buffer[i].buf.field = V4L2_FIELD_NONE;
> - queue->buffer[i].buf.memory = V4L2_MEMORY_MMAP;
> - queue->buffer[i].buf.flags = 0;
> - init_waitqueue_head(&queue->buffer[i].wait);
> + if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
> + list_add_tail(&buf->queue, &queue->irqqueue);
> + } else {
> + /* If the device is disconnected return the buffer to userspace
> + * directly. The next QBUF call will fail with -ENODEV.
> + */
> + buf->state = UVC_BUF_STATE_ERROR;
> + vb2_buffer_done(&buf->buf, VB2_BUF_STATE_ERROR);
> }
>
> - queue->mem = mem;
> - queue->count = nbuffers;
> - queue->buf_size = bufsize;
> - ret = nbuffers;
> -
> -done:
> - mutex_unlock(&queue->mutex);
> - return ret;
> + spin_unlock_irqrestore(&queue->irqlock, flags);
> }
>
> -static void __uvc_query_buffer(struct uvc_buffer *buf,
> - struct v4l2_buffer *v4l2_buf)
> -{
> - memcpy(v4l2_buf, &buf->buf, sizeof *v4l2_buf);
> -
> - if (buf->vma_use_count)
> - v4l2_buf->flags |= V4L2_BUF_FLAG_MAPPED;
> -
> - switch (buf->state) {
> - case UVC_BUF_STATE_ERROR:
> - case UVC_BUF_STATE_DONE:
> - v4l2_buf->flags |= V4L2_BUF_FLAG_DONE;
> - break;
> - case UVC_BUF_STATE_QUEUED:
> - case UVC_BUF_STATE_ACTIVE:
> - v4l2_buf->flags |= V4L2_BUF_FLAG_QUEUED;
> - break;
> - case UVC_BUF_STATE_IDLE:
> - default:
> - break;
> - }
> -}
> +static struct vb2_ops uvc_queue_qops = {
> + .queue_setup = uvc_queue_setup,
> + .buf_prepare = uvc_buffer_prepare,
> + .buf_queue = uvc_buffer_queue,
> +};
>
> -static int
> -uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *v4l2_buf)
> +static int uvc_queue_init(struct uvc_video_queue *queue,
> + enum v4l2_buf_type type)
> {
> - int ret = 0;
> + int ret;
>
> - mutex_lock(&queue->mutex);
> - if (v4l2_buf->index >= queue->count) {
> - ret = -EINVAL;
> - goto done;
> - }
> + queue->queue.type = type;
> + queue->queue.io_modes = VB2_MMAP | VB2_USERPTR;
> + queue->queue.drv_priv = queue;
> + queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
> + queue->queue.ops = &uvc_queue_qops;
> + queue->queue.mem_ops = &vb2_vmalloc_memops;
> + ret = vb2_queue_init(&queue->queue);
> + if (ret)
> + return ret;
>
> - __uvc_query_buffer(&queue->buffer[v4l2_buf->index], v4l2_buf);
> + mutex_init(&queue->mutex);
> + spin_lock_init(&queue->irqlock);
> + INIT_LIST_HEAD(&queue->irqqueue);
>
> -done:
> - mutex_unlock(&queue->mutex);
> - return ret;
> + return 0;
> }
>
> /*
> - * Queue a video buffer. Attempting to queue a buffer that has already been
> - * queued will return -EINVAL.
> + * Free the video buffers.
> */
> -static int
> -uvc_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *v4l2_buf)
> +static void uvc_free_buffers(struct uvc_video_queue *queue)
> {
> - struct uvc_buffer *buf;
> - unsigned long flags;
> - int ret = 0;
> -
> - uvc_trace(UVC_TRACE_CAPTURE, "Queuing buffer %u.\n", v4l2_buf->index);
> -
> - if (v4l2_buf->type != queue->type ||
> - v4l2_buf->memory != V4L2_MEMORY_MMAP) {
> - uvc_trace(UVC_TRACE_CAPTURE, "[E] Invalid buffer type (%u) "
> - "and/or memory (%u).\n", v4l2_buf->type,
> - v4l2_buf->memory);
> - return -EINVAL;
> - }
> -
> mutex_lock(&queue->mutex);
> - if (v4l2_buf->index >= queue->count) {
> - uvc_trace(UVC_TRACE_CAPTURE, "[E] Out of range index.\n");
> - ret = -EINVAL;
> - goto done;
> - }
> -
> - buf = &queue->buffer[v4l2_buf->index];
> - if (buf->state != UVC_BUF_STATE_IDLE) {
> - uvc_trace(UVC_TRACE_CAPTURE, "[E] Invalid buffer state "
> - "(%u).\n", buf->state);
> - ret = -EINVAL;
> - goto done;
> - }
> -
> - if (v4l2_buf->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
> - v4l2_buf->bytesused > buf->buf.length) {
> - uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
> - ret = -EINVAL;
> - goto done;
> - }
> + vb2_queue_release(&queue->queue);
> + mutex_unlock(&queue->mutex);
> +}
>
> - if (v4l2_buf->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
> - buf->buf.bytesused = 0;
> - else
> - buf->buf.bytesused = v4l2_buf->bytesused;
> +/*
> + * Allocate the video buffers.
> + */
> +static int uvc_alloc_buffers(struct uvc_video_queue *queue,
> + struct v4l2_requestbuffers *rb)
> +{
> + int ret;
>
> - spin_lock_irqsave(&queue->irqlock, flags);
> - if (queue->flags & UVC_QUEUE_DISCONNECTED) {
> - spin_unlock_irqrestore(&queue->irqlock, flags);
> - ret = -ENODEV;
> - goto done;
> - }
> - buf->state = UVC_BUF_STATE_QUEUED;
> + mutex_lock(&queue->mutex);
> + ret = vb2_reqbufs(&queue->queue, rb);
> + mutex_unlock(&queue->mutex);
>
> - ret = (queue->flags & UVC_QUEUE_PAUSED) != 0;
> - queue->flags &= ~UVC_QUEUE_PAUSED;
> + return ret ? ret : rb->count;
> +}
>
> - list_add_tail(&buf->stream, &queue->mainqueue);
> - list_add_tail(&buf->queue, &queue->irqqueue);
> - spin_unlock_irqrestore(&queue->irqlock, flags);
> +static int uvc_query_buffer(struct uvc_video_queue *queue,
> + struct v4l2_buffer *buf)
> +{
> + int ret;
>
> -done:
> + mutex_lock(&queue->mutex);
> + ret = vb2_querybuf(&queue->queue, buf);
> mutex_unlock(&queue->mutex);
> +
> return ret;
> }
>
> -static int uvc_queue_waiton(struct uvc_buffer *buf, int nonblocking)
> +static int uvc_queue_buffer(struct uvc_video_queue *queue,
> + struct v4l2_buffer *buf)
> {
> - if (nonblocking) {
> - return (buf->state != UVC_BUF_STATE_QUEUED &&
> - buf->state != UVC_BUF_STATE_ACTIVE)
> - ? 0 : -EAGAIN;
> - }
> + int ret;
>
> - return wait_event_interruptible(buf->wait,
> - buf->state != UVC_BUF_STATE_QUEUED &&
> - buf->state != UVC_BUF_STATE_ACTIVE);
> + mutex_lock(&queue->mutex);
> + ret = vb2_qbuf(&queue->queue, buf);
> + mutex_unlock(&queue->mutex);
> +
How is the UVC_QUEUE_PAUSED handling supposed to be handled here?
I see that this patch lost this hunk from uvc_queue_buffer():
ret |= (queue->flags & uvc_queue_paused) != 0;
queue->flags &= ~UVC_QUEUE_PAUSED;
> + return ret;
> }
>
> /*
> * Dequeue a video buffer. If nonblocking is false, block until a buffer is
> * available.
> */
> -static int
> -uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer
> *v4l2_buf,
> - int nonblocking)
> +static int uvc_dequeue_buffer(struct uvc_video_queue *queue,
> + struct v4l2_buffer *buf, int nonblocking)
> {
> - struct uvc_buffer *buf;
> - int ret = 0;
> -
> - if (v4l2_buf->type != queue->type ||
> - v4l2_buf->memory != V4L2_MEMORY_MMAP) {
> - uvc_trace(UVC_TRACE_CAPTURE, "[E] Invalid buffer type (%u) "
> - "and/or memory (%u).\n", v4l2_buf->type,
> - v4l2_buf->memory);
> - return -EINVAL;
> - }
> + int ret;
>
> mutex_lock(&queue->mutex);
> - if (list_empty(&queue->mainqueue)) {
> - uvc_trace(UVC_TRACE_CAPTURE, "[E] Empty buffer queue.\n");
> - ret = -EINVAL;
> - goto done;
> - }
> -
> - buf = list_first_entry(&queue->mainqueue, struct uvc_buffer, stream);
> - if ((ret = uvc_queue_waiton(buf, nonblocking)) < 0)
> - goto done;
> -
> - uvc_trace(UVC_TRACE_CAPTURE, "Dequeuing buffer %u (%u, %u bytes).\n",
> - buf->buf.index, buf->state, buf->buf.bytesused);
> -
> - switch (buf->state) {
> - case UVC_BUF_STATE_ERROR:
> - uvc_trace(UVC_TRACE_CAPTURE, "[W] Corrupted data "
> - "(transmission error).\n");
> - ret = -EIO;
> - case UVC_BUF_STATE_DONE:
> - buf->state = UVC_BUF_STATE_IDLE;
> - break;
> -
> - case UVC_BUF_STATE_IDLE:
> - case UVC_BUF_STATE_QUEUED:
> - case UVC_BUF_STATE_ACTIVE:
> - default:
> - uvc_trace(UVC_TRACE_CAPTURE, "[E] Invalid buffer state %u "
> - "(driver bug?).\n", buf->state);
> - ret = -EINVAL;
> - goto done;
> - }
> -
> - list_del(&buf->stream);
> - __uvc_query_buffer(buf, v4l2_buf);
> -
> -done:
> + ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
> mutex_unlock(&queue->mutex);
> +
> return ret;
> }
>
> @@ -361,103 +202,27 @@ done:
> * This function implements video queue polling and is intended to be used by
> * the device poll handler.
> */
> -static unsigned int
> -uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
> - poll_table *wait)
> +static unsigned int uvc_queue_poll(struct uvc_video_queue *queue,
> + struct file *file, poll_table *wait)
> {
> - struct uvc_buffer *buf;
> - unsigned int mask = 0;
> + unsigned int ret;
>
> mutex_lock(&queue->mutex);
> - if (list_empty(&queue->mainqueue))
> - goto done;
> -
> - buf = list_first_entry(&queue->mainqueue, struct uvc_buffer, stream);
> -
> - poll_wait(file, &buf->wait, wait);
> - if (buf->state == UVC_BUF_STATE_DONE ||
> - buf->state == UVC_BUF_STATE_ERROR)
> - mask |= POLLOUT | POLLWRNORM;
> -
> -done:
> + ret = vb2_poll(&queue->queue, file, wait);
> mutex_unlock(&queue->mutex);
> - return mask;
> -}
>
> -/*
> - * VMA operations.
> - */
> -static void uvc_vm_open(struct vm_area_struct *vma)
> -{
> - struct uvc_buffer *buffer = vma->vm_private_data;
> - buffer->vma_use_count++;
> + return ret;
> }
>
> -static void uvc_vm_close(struct vm_area_struct *vma)
> +static int uvc_queue_mmap(struct uvc_video_queue *queue,
> + struct vm_area_struct *vma)
> {
> - struct uvc_buffer *buffer = vma->vm_private_data;
> - buffer->vma_use_count--;
> -}
> -
> -static struct vm_operations_struct uvc_vm_ops = {
> - .open = uvc_vm_open,
> - .close = uvc_vm_close,
> -};
> -
> -/*
> - * Memory-map a buffer.
> - *
> - * This function implements video buffer memory mapping and is intended to be
> - * used by the device mmap handler.
> - */
> -static int
> -uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
> -{
> - struct uvc_buffer *uninitialized_var(buffer);
> - struct page *page;
> - unsigned long addr, start, size;
> - unsigned int i;
> - int ret = 0;
> -
> - start = vma->vm_start;
> - size = vma->vm_end - vma->vm_start;
> + int ret;
>
> mutex_lock(&queue->mutex);
> -
> - for (i = 0; i < queue->count; ++i) {
> - buffer = &queue->buffer[i];
> - if ((buffer->buf.m.offset >> PAGE_SHIFT) == vma->vm_pgoff)
> - break;
> - }
> -
> - if (i == queue->count || size != queue->buf_size) {
> - ret = -EINVAL;
> - goto done;
> - }
> -
> - /*
> - * VM_IO marks the area as being an mmaped region for I/O to a
> - * device. It also prevents the region from being core dumped.
> - */
> - vma->vm_flags |= VM_IO;
> -
> - addr = (unsigned long)queue->mem + buffer->buf.m.offset;
> - while (size > 0) {
> - page = vmalloc_to_page((void *)addr);
> - if ((ret = vm_insert_page(vma, start, page)) < 0)
> - goto done;
> -
> - start += PAGE_SIZE;
> - addr += PAGE_SIZE;
> - size -= PAGE_SIZE;
> - }
> -
> - vma->vm_ops = &uvc_vm_ops;
> - vma->vm_private_data = buffer;
> - uvc_vm_open(vma);
> -
> -done:
> + ret = vb2_mmap(&queue->queue, vma);
> mutex_unlock(&queue->mutex);
> +
> return ret;
> }
>
> @@ -484,9 +249,10 @@ static void uvc_queue_cancel(struct uvc_video_queue
> *queue, int disconnect)
> queue);
> list_del(&buf->queue);
> buf->state = UVC_BUF_STATE_ERROR;
> - wake_up(&buf->wait);
> + vb2_buffer_done(&buf->buf, VB2_BUF_STATE_ERROR);
> }
> - /* This must be protected by the irqlock spinlock to avoid race
> + /*
> + * This must be protected by the irqlock spinlock to avoid race
> * conditions between uvc_queue_buffer and the disconnection event that
> * could result in an interruptible wait in uvc_dequeue_buffer. Do not
> * blindly replace this logic by checking for the UVC_DEV_DISCONNECTED
> @@ -516,26 +282,34 @@ static void uvc_queue_cancel(struct uvc_video_queue
> *queue, int disconnect)
> */
> static int uvc_queue_enable(struct uvc_video_queue *queue, int enable)
> {
> - unsigned int i;
> + unsigned long flags;
> int ret = 0;
>
> mutex_lock(&queue->mutex);
> if (enable) {
> - if (uvc_queue_streaming(queue)) {
> - ret = -EBUSY;
> + ret = vb2_streamon(&queue->queue, queue->queue.type);
> + if (ret < 0)
> goto done;
> - }
> - queue->sequence = 0;
> - queue->flags |= UVC_QUEUE_STREAMING;
> +
> queue->buf_used = 0;
> } else {
> - uvc_queue_cancel(queue, 0);
> - INIT_LIST_HEAD(&queue->mainqueue);
> + ret = vb2_streamoff(&queue->queue, queue->queue.type);
> + if (ret < 0)
> + goto done;
> +
> + spin_lock_irqsave(&queue->irqlock, flags);
> +
> + INIT_LIST_HEAD(&queue->irqqueue);
>
> - for (i = 0; i < queue->count; ++i)
> - queue->buffer[i].state = UVC_BUF_STATE_IDLE;
> + /*
> + * FIXME: We need to clear the DISCONNECTED flag to ensure that
> + * applications will be able to queue buffers for the next
> + * streaming run. However, clearing it here doesn't guarantee
> + * that the device will be reconnected in the meantime.
> + */
> + queue->flags &= ~UVC_QUEUE_DISCONNECTED;
>
> - queue->flags &= ~UVC_QUEUE_STREAMING;
> + spin_unlock_irqrestore(&queue->irqlock, flags);
> }
>
> done:
> @@ -544,15 +318,15 @@ done:
> }
>
> /* called with &queue_irqlock held.. */
> -static struct uvc_buffer *
> -uvc_queue_next_buffer(struct uvc_video_queue *queue, struct uvc_buffer *buf)
> +static struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue
> *queue,
> + struct uvc_buffer *buf)
> {
> struct uvc_buffer *nextbuf;
>
> if ((queue->flags & UVC_QUEUE_DROP_INCOMPLETE) &&
> - buf->buf.length != buf->buf.bytesused) {
> + buf->length != buf->bytesused) {
> buf->state = UVC_BUF_STATE_QUEUED;
> - buf->buf.bytesused = 0;
> + vb2_set_plane_payload(&buf->buf, 0, 0);
> return buf;
> }
>
> @@ -563,10 +337,18 @@ uvc_queue_next_buffer(struct uvc_video_queue *queue,
> struct uvc_buffer *buf)
> else
> nextbuf = NULL;
>
> - buf->buf.sequence = queue->sequence++;
> - do_gettimeofday(&buf->buf.timestamp);
> + /*
> + * FIXME: with videobuf2, the sequence number or timestamp fields
> + * are valid only for video capture devices and the UVC gadget usually
> + * is a video output device. Keeping these until the specs are clear on
> + * this aspect.
> + */
> + buf->buf.v4l2_buf.sequence = queue->sequence++;
> + do_gettimeofday(&buf->buf.v4l2_buf.timestamp);
> +
> + vb2_set_plane_payload(&buf->buf, 0, buf->bytesused);
> + vb2_buffer_done(&buf->buf, VB2_BUF_STATE_DONE);
>
> - wake_up(&buf->wait);
> return nextbuf;
> }
>
> @@ -582,4 +364,3 @@ static struct uvc_buffer *uvc_queue_head(struct
> uvc_video_queue *queue)
>
> return buf;
> }
> -
> diff --git a/drivers/usb/gadget/uvc_queue.h b/drivers/usb/gadget/uvc_queue.h
> index 1812a8e..47ad0b8 100644
> --- a/drivers/usb/gadget/uvc_queue.h
> +++ b/drivers/usb/gadget/uvc_queue.h
> @@ -6,6 +6,7 @@
> #include <linux/kernel.h>
> #include <linux/poll.h>
> #include <linux/videodev2.h>
> +#include <media/videobuf2-core.h>
>
> /* Maximum frame size in bytes, for sanity checking. */
> #define UVC_MAX_FRAME_SIZE (16*1024*1024)
> @@ -25,14 +26,13 @@ enum uvc_buffer_state {
> };
>
> struct uvc_buffer {
> - unsigned long vma_use_count;
> - struct list_head stream;
> -
> - /* Touched by interrupt handler. */
> - struct v4l2_buffer buf;
> + struct vb2_buffer buf;
> struct list_head queue;
> - wait_queue_head_t wait;
> +
> enum uvc_buffer_state state;
> + void *mem;
> + unsigned int length;
> + unsigned int bytesused;
> };
>
> #define UVC_QUEUE_STREAMING (1 << 0)
> @@ -41,26 +41,21 @@ struct uvc_buffer {
> #define UVC_QUEUE_PAUSED (1 << 3)
>
> struct uvc_video_queue {
> - enum v4l2_buf_type type;
> + struct vb2_queue queue;
> + struct mutex mutex; /* Protects queue */
>
> - void *mem;
> unsigned int flags;
> __u32 sequence;
>
> - unsigned int count;
> - unsigned int buf_size;
> unsigned int buf_used;
> - struct uvc_buffer buffer[UVC_MAX_VIDEO_BUFFERS];
> - struct mutex mutex; /* protects buffers and mainqueue */
> - spinlock_t irqlock; /* protects irqqueue */
>
> - struct list_head mainqueue;
> + spinlock_t irqlock; /* Protects irqqueue */
> struct list_head irqqueue;
> };
>
> static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
> {
> - return queue->flags & UVC_QUEUE_STREAMING;
> + return vb2_is_streaming(&queue->queue);
> }
>
> #endif /* __KERNEL__ */
> diff --git a/drivers/usb/gadget/uvc_v4l2.c b/drivers/usb/gadget/uvc_v4l2.c
> index 2ca9386..134bfe5 100644
> --- a/drivers/usb/gadget/uvc_v4l2.c
> +++ b/drivers/usb/gadget/uvc_v4l2.c
> @@ -148,16 +148,13 @@ uvc_v4l2_release(struct file *file)
> uvc_function_disconnect(uvc);
>
> uvc_video_enable(video, 0);
> - mutex_lock(&video->queue.mutex);
> - if (uvc_free_buffers(&video->queue) < 0)
> - printk(KERN_ERR "uvc_v4l2_release: Unable to free "
> - "buffers.\n");
> - mutex_unlock(&video->queue.mutex);
> + uvc_free_buffers(&video->queue);
>
> file->private_data = NULL;
> v4l2_fh_del(&handle->vfh);
> v4l2_fh_exit(&handle->vfh);
> kfree(handle);
> +
> return 0;
> }
>
> @@ -192,7 +189,7 @@ uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd,
> void *arg)
> {
> struct v4l2_format *fmt = arg;
>
> - if (fmt->type != video->queue.type)
> + if (fmt->type != video->queue.queue.type)
> return -EINVAL;
>
> return uvc_v4l2_get_format(video, fmt);
> @@ -202,7 +199,7 @@ uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd,
> void *arg)
> {
> struct v4l2_format *fmt = arg;
>
> - if (fmt->type != video->queue.type)
> + if (fmt->type != video->queue.queue.type)
> return -EINVAL;
>
> return uvc_v4l2_set_format(video, fmt);
> @@ -213,16 +210,13 @@ uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd,
> void *arg)
> {
> struct v4l2_requestbuffers *rb = arg;
>
> - if (rb->type != video->queue.type ||
> - rb->memory != V4L2_MEMORY_MMAP)
> + if (rb->type != video->queue.queue.type)
> return -EINVAL;
>
> - ret = uvc_alloc_buffers(&video->queue, rb->count,
> - video->imagesize);
> + ret = uvc_alloc_buffers(&video->queue, rb);
> if (ret < 0)
> return ret;
>
> - rb->count = ret;
> ret = 0;
> break;
> }
> @@ -231,9 +225,6 @@ uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd,
> void *arg)
> {
> struct v4l2_buffer *buf = arg;
>
> - if (buf->type != video->queue.type)
> - return -EINVAL;
> -
> return uvc_query_buffer(&video->queue, buf);
> }
>
> @@ -251,7 +242,7 @@ uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd,
> void *arg)
> {
> int *type = arg;
>
> - if (*type != video->queue.type)
> + if (*type != video->queue.queue.type)
> return -EINVAL;
>
> return uvc_video_enable(video, 1);
> @@ -261,14 +252,14 @@ uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd,
> void *arg)
> {
> int *type = arg;
>
> - if (*type != video->queue.type)
> + if (*type != video->queue.queue.type)
> return -EINVAL;
>
> return uvc_video_enable(video, 0);
> }
>
> /* Events */
> - case VIDIOC_DQEVENT:
> + case VIDIOC_DQEVENT:
> {
> struct v4l2_event *event = arg;
>
> diff --git a/drivers/usb/gadget/uvc_video.c b/drivers/usb/gadget/uvc_video.c
> index f7d1913..2e06f24 100644
> --- a/drivers/usb/gadget/uvc_video.c
> +++ b/drivers/usb/gadget/uvc_video.c
> @@ -32,7 +32,7 @@ uvc_video_encode_header(struct uvc_video *video, struct
> uvc_buffer *buf,
> data[0] = 2;
> data[1] = UVC_STREAM_EOH | video->fid;
>
> - if (buf->buf.bytesused - video->queue.buf_used <= len - 2)
> + if (buf->bytesused - video->queue.buf_used <= len - 2)
> data[1] |= UVC_STREAM_EOF;
>
> return 2;
> @@ -47,8 +47,8 @@ uvc_video_encode_data(struct uvc_video *video, struct
> uvc_buffer *buf,
> void *mem;
>
> /* Copy video data to the USB buffer. */
> - mem = queue->mem + buf->buf.m.offset + queue->buf_used;
> - nbytes = min((unsigned int)len, buf->buf.bytesused - queue->buf_used);
> + mem = buf->mem + queue->buf_used;
> + nbytes = min((unsigned int)len, buf->bytesused - queue->buf_used);
>
> memcpy(data, mem, nbytes);
> queue->buf_used += nbytes;
> @@ -82,7 +82,7 @@ uvc_video_encode_bulk(struct usb_request *req, struct
> uvc_video *video,
> req->length = video->req_size - len;
> req->zero = video->payload_size == video->max_payload_size;
>
> - if (buf->buf.bytesused == video->queue.buf_used) {
> + if (buf->bytesused == video->queue.buf_used) {
> video->queue.buf_used = 0;
> buf->state = UVC_BUF_STATE_DONE;
> uvc_queue_next_buffer(&video->queue, buf);
> @@ -92,7 +92,7 @@ uvc_video_encode_bulk(struct usb_request *req, struct
> uvc_video *video,
> }
>
> if (video->payload_size == video->max_payload_size ||
> - buf->buf.bytesused == video->queue.buf_used)
> + buf->bytesused == video->queue.buf_used)
> video->payload_size = 0;
> }
>
> @@ -115,7 +115,7 @@ uvc_video_encode_isoc(struct usb_request *req, struct
> uvc_video *video,
>
> req->length = video->req_size - len;
>
> - if (buf->buf.bytesused == video->queue.buf_used) {
> + if (buf->bytesused == video->queue.buf_used) {
> video->queue.buf_used = 0;
> buf->state = UVC_BUF_STATE_DONE;
> uvc_queue_next_buffer(&video->queue, buf);
> @@ -161,6 +161,7 @@ static void
> uvc_video_complete(struct usb_ep *ep, struct usb_request *req)
> {
> struct uvc_video *video = req->context;
> + struct uvc_video_queue *queue = &video->queue;
> struct uvc_buffer *buf;
> unsigned long flags;
> int ret;
> @@ -169,13 +170,15 @@ uvc_video_complete(struct usb_ep *ep, struct
> usb_request *req)
> case 0:
> break;
>
> - case -ESHUTDOWN:
> + case -ESHUTDOWN: /* disconnect from host. */
> printk(KERN_INFO "VS request cancelled.\n");
> + uvc_queue_cancel(queue, 1);
> goto requeue;
>
> default:
> printk(KERN_INFO "VS request completed with status %d.\n",
> req->status);
> + uvc_queue_cancel(queue, 0);
> goto requeue;
> }
>
> @@ -387,4 +390,3 @@ uvc_video_init(struct uvc_video *video)
> uvc_queue_init(&video->queue, V4L2_BUF_TYPE_VIDEO_OUTPUT);
> return 0;
> }
> -
> --
> 1.7.2.2
>
> --
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>
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