Re: [PATCH v3 2/3] media: au0828 - convert to use videobuf2

Lad, Prabhakar
2015-01-22T20:48:34Z

Hi Shuah,

On Thu, Jan 22, 2015 at 4:16 PM, Shuah Khan <shuahkh@osg.samsung.com> wrote:
> Hi Prabhakar,
>
[snip]
>>> + buf->vb.v4l2_buf.field = V4L2_FIELD_INTERLACED;
>>> + v4l2_get_timestamp(&buf->vb.v4l2_buf.timestamp);
>>> + vb2_buffer_done(&buf->vb, VB2_BUF_STATE_DONE);
>>> }
>>>
>> Why not just have one single buffer_filled function ? just check the
>> queue type and assign the dev->isoc_ctl.buf/ dev->isoc_ctl.vbi_buf
>> to NULL.
>
> Yes. These two routines could be collapsed into a single. Is it okay if
> I made that change in a separate patch?
>
hmm.. this can go as a separate patch.

>>
>>> /*
>>> @@ -353,8 +340,8 @@ static void au0828_copy_video(struct au0828_dev *dev,
>>> if (len == 0)
>>> return;
>>>
>>> - if (dma_q->pos + len > buf->vb.size)
>>> - len = buf->vb.size - dma_q->pos;
>>> + if (dma_q->pos + len > buf->length)
>>> + len = buf->length - dma_q->pos;
>>>
>>> startread = p;
>>> remain = len;
>>> @@ -372,11 +359,11 @@ static void au0828_copy_video(struct au0828_dev *dev,
>>> lencopy = bytesperline - currlinedone;
>>> lencopy = lencopy > remain ? remain : lencopy;
>>>
>>> - if ((char *)startwrite + lencopy > (char *)outp + buf->vb.size) {
>>> + if ((char *)startwrite + lencopy > (char *)outp + buf->length) {
>>> au0828_isocdbg("Overflow of %zi bytes past buffer end (1)\n",
>>> ((char *)startwrite + lencopy) -
>>> - ((char *)outp + buf->vb.size));
>>> - remain = (char *)outp + buf->vb.size - (char *)startwrite;
>>> + ((char *)outp + buf->length));
>>> + remain = (char *)outp + buf->length - (char *)startwrite;
>>> lencopy = remain;
>>> }
>>> if (lencopy <= 0)
>>> @@ -394,11 +381,11 @@ static void au0828_copy_video(struct au0828_dev *dev,
>>> lencopy = bytesperline;
>>>
>>> if ((char *)startwrite + lencopy > (char *)outp +
>>> - buf->vb.size) {
>>> + buf->length) {
>>> au0828_isocdbg("Overflow %zi bytes past buf end (2)\n",
>>> ((char *)startwrite + lencopy) -
>>> - ((char *)outp + buf->vb.size));
>>> - lencopy = remain = (char *)outp + buf->vb.size -
>>> + ((char *)outp + buf->length));
>>> + lencopy = remain = (char *)outp + buf->length -
>>> (char *)startwrite;
>>> }
>>> if (lencopy <= 0)
>>> @@ -434,7 +421,11 @@ static inline void get_next_buf(struct au0828_dmaqueue *dma_q,
>>> }
>>>
>>> /* Get the next buffer */
>>> - *buf = list_entry(dma_q->active.next, struct au0828_buffer, vb.queue);
>>> + *buf = list_entry(dma_q->active.next, struct au0828_buffer, list);
>>> + /* Cleans up buffer - Useful for testing for frame/URB loss */
>>> + list_del(&(*buf)->list);
>>> + dma_q->pos = 0;
>>> + (*buf)->vb_buf = (*buf)->mem;
>>> dev->isoc_ctl.buf = *buf;
>>>
>>> return;
>>> @@ -472,8 +463,8 @@ static void au0828_copy_vbi(struct au0828_dev *dev,
>>>
>>> bytesperline = dev->vbi_width;
>>>
>>> - if (dma_q->pos + len > buf->vb.size)
>>> - len = buf->vb.size - dma_q->pos;
>>> + if (dma_q->pos + len > buf->length)
>>> + len = buf->length - dma_q->pos;
>>>
>>> startread = p;
>>> startwrite = outp + (dma_q->pos / 2);
>>> @@ -496,7 +487,6 @@ static inline void vbi_get_next_buf(struct au0828_dmaqueue *dma_q,
>>> struct au0828_buffer **buf)
>>> {
>>> struct au0828_dev *dev = container_of(dma_q, struct au0828_dev, vbiq);
>>> - char *outp;
>>>
>>> if (list_empty(&dma_q->active)) {
>>> au0828_isocdbg("No active queue to serve\n");
>>> @@ -506,13 +496,12 @@ static inline void vbi_get_next_buf(struct au0828_dmaqueue *dma_q,
>>> }
>>>
>>> /* Get the next buffer */
>>> - *buf = list_entry(dma_q->active.next, struct au0828_buffer, vb.queue);
>>> + *buf = list_entry(dma_q->active.next, struct au0828_buffer, list);
>>> /* Cleans up buffer - Useful for testing for frame/URB loss */
>>> - outp = videobuf_to_vmalloc(&(*buf)->vb);
>>> - memset(outp, 0x00, (*buf)->vb.size);
>>> -
>>> + list_del(&(*buf)->list);
>>> + dma_q->pos = 0;
>>> + (*buf)->vb_buf = (*buf)->mem;
>>> dev->isoc_ctl.vbi_buf = *buf;
>>> -
>>> return;
>>> }
>>>
>>> @@ -548,11 +537,11 @@ static inline int au0828_isoc_copy(struct au0828_dev *dev, struct urb *urb)
>>>
>>> buf = dev->isoc_ctl.buf;
>>> if (buf != NULL)
>>> - outp = videobuf_to_vmalloc(&buf->vb);
>>> + outp = vb2_plane_vaddr(&buf->vb, 0);
>>>
>>> vbi_buf = dev->isoc_ctl.vbi_buf;
>>> if (vbi_buf != NULL)
>>> - vbioutp = videobuf_to_vmalloc(&vbi_buf->vb);
>>> + vbioutp = vb2_plane_vaddr(&vbi_buf->vb, 0);
>>>
>>> for (i = 0; i < urb->number_of_packets; i++) {
>>> int status = urb->iso_frame_desc[i].status;
>>> @@ -592,8 +581,8 @@ static inline int au0828_isoc_copy(struct au0828_dev *dev, struct urb *urb)
>>> if (vbi_buf == NULL)
>>> vbioutp = NULL;
>>> else
>>> - vbioutp = videobuf_to_vmalloc(
>>> - &vbi_buf->vb);
>>> + vbioutp = vb2_plane_vaddr(
>>> + &vbi_buf->vb, 0);
>>>
>>> /* Video */
>>> if (buf != NULL)
>>> @@ -602,7 +591,7 @@ static inline int au0828_isoc_copy(struct au0828_dev *dev, struct urb *urb)
>>> if (buf == NULL)
>>> outp = NULL;
>>> else
>>> - outp = videobuf_to_vmalloc(&buf->vb);
>>> + outp = vb2_plane_vaddr(&buf->vb, 0);
>>>
>>> /* As long as isoc traffic is arriving, keep
>>> resetting the timer */
>>> @@ -656,130 +645,59 @@ static inline int au0828_isoc_copy(struct au0828_dev *dev, struct urb *urb)
>>> return rc;
>>> }
>>>
>>> -static int
>>> -buffer_setup(struct videobuf_queue *vq, unsigned int *count,
>>> - unsigned int *size)
>>> +static int queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt,
>>> + unsigned int *nbuffers, unsigned int *nplanes,
>>> + unsigned int sizes[], void *alloc_ctxs[])
>>> {
>>> - struct au0828_fh *fh = vq->priv_data;
>>> - *size = (fh->dev->width * fh->dev->height * 16 + 7) >> 3;
>>> -
>>> - if (0 == *count)
>>> - *count = AU0828_DEF_BUF;
>>> + struct au0828_dev *dev = vb2_get_drv_priv(vq);
>>> + unsigned long img_size = dev->height * dev->bytesperline;
>>> + unsigned long size;
>>>
>>> - if (*count < AU0828_MIN_BUF)
>>> - *count = AU0828_MIN_BUF;
>>> - return 0;
>>> -}
>>> + size = fmt ? fmt->fmt.pix.sizeimage : img_size;
>>> + if (size < img_size)
>>> + return -EINVAL;
>>>
>>> -/* This is called *without* dev->slock held; please keep it that way */
>>> -static void free_buffer(struct videobuf_queue *vq, struct au0828_buffer *buf)
>>> -{
>>> - struct au0828_fh *fh = vq->priv_data;
>>> - struct au0828_dev *dev = fh->dev;
>>> - unsigned long flags = 0;
>>> - if (in_interrupt())
>>> - BUG();
>>> -
>>> - /* We used to wait for the buffer to finish here, but this didn't work
>>> - because, as we were keeping the state as VIDEOBUF_QUEUED,
>>> - videobuf_queue_cancel marked it as finished for us.
>>> - (Also, it could wedge forever if the hardware was misconfigured.)
>>> -
>>> - This should be safe; by the time we get here, the buffer isn't
>>> - queued anymore. If we ever start marking the buffers as
>>> - VIDEOBUF_ACTIVE, it won't be, though.
>>> - */
>>> - spin_lock_irqsave(&dev->slock, flags);
>>> - if (dev->isoc_ctl.buf == buf)
>>> - dev->isoc_ctl.buf = NULL;
>>> - spin_unlock_irqrestore(&dev->slock, flags);
>>> + *nplanes = 1;
>>> + sizes[0] = size;
>>>
>>> - videobuf_vmalloc_free(&buf->vb);
>>> - buf->vb.state = VIDEOBUF_NEEDS_INIT;
>>> + return 0;
>>> }
>>>
>>> static int
>>> -buffer_prepare(struct videobuf_queue *vq, struct videobuf_buffer *vb,
>>> - enum v4l2_field field)
>>> +buffer_prepare(struct vb2_buffer *vb)
>>> {
>>> - struct au0828_fh *fh = vq->priv_data;
>>> struct au0828_buffer *buf = container_of(vb, struct au0828_buffer, vb);
>>> - struct au0828_dev *dev = fh->dev;
>>> - int rc = 0, urb_init = 0;
>>> + struct au0828_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
>>>
>>> - buf->vb.size = (fh->dev->width * fh->dev->height * 16 + 7) >> 3;
>>> + buf->length = dev->height * dev->bytesperline;
>>>
>>> - if (0 != buf->vb.baddr && buf->vb.bsize < buf->vb.size)
>>> + if (vb2_plane_size(vb, 0) < buf->length) {
>>> + pr_err("%s data will not fit into plane (%lu < %lu)\n",
>>> + __func__, vb2_plane_size(vb, 0), buf->length);
>>> return -EINVAL;
>>> -
>>> - buf->vb.width = dev->width;
>>> - buf->vb.height = dev->height;
>>> - buf->vb.field = field;
>>> -
>>> - if (VIDEOBUF_NEEDS_INIT == buf->vb.state) {
>>> - rc = videobuf_iolock(vq, &buf->vb, NULL);
>>> - if (rc < 0) {
>>> - pr_info("videobuf_iolock failed\n");
>>> - goto fail;
>>> - }
>>> }
>>> -
>>> - if (!dev->isoc_ctl.num_bufs)
>>> - urb_init = 1;
>>> -
>>> - if (urb_init) {
>>> - rc = au0828_init_isoc(dev, AU0828_ISO_PACKETS_PER_URB,
>>> - AU0828_MAX_ISO_BUFS, dev->max_pkt_size,
>>> - au0828_isoc_copy);
>>> - if (rc < 0) {
>>> - pr_info("au0828_init_isoc failed\n");
>>> - goto fail;
>>> - }
>>> - }
>>> -
>>> - buf->vb.state = VIDEOBUF_PREPARED;
>>> + vb2_set_plane_payload(&buf->vb, 0, buf->length);
>>> return 0;
>>> -
>>> -fail:
>>> - free_buffer(vq, buf);
>>> - return rc;
>>> }
>>>
>>> static void
>>> -buffer_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb)
>>> +buffer_queue(struct vb2_buffer *vb)
>>> {
>>> struct au0828_buffer *buf = container_of(vb,
>>> struct au0828_buffer,
>>> vb);
>>> - struct au0828_fh *fh = vq->priv_data;
>>> - struct au0828_dev *dev = fh->dev;
>>> + struct au0828_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
>>> struct au0828_dmaqueue *vidq = &dev->vidq;
>>> + unsigned long flags = 0;
>>>
>>> - buf->vb.state = VIDEOBUF_QUEUED;
>>> - list_add_tail(&buf->vb.queue, &vidq->active);
>>> -}
>>> -
>>> -static void buffer_release(struct videobuf_queue *vq,
>>> - struct videobuf_buffer *vb)
>>> -{
>>> - struct au0828_buffer *buf = container_of(vb,
>>> - struct au0828_buffer,
>>> - vb);
>>> + buf->mem = vb2_plane_vaddr(vb, 0);
>>> + buf->length = vb2_plane_size(vb, 0);
>>>
>>> - free_buffer(vq, buf);
>>> + spin_lock_irqsave(&dev->slock, flags);
>>> + list_add_tail(&buf->list, &vidq->active);
>>> + spin_unlock_irqrestore(&dev->slock, flags);
>>> }
>>>
>>> -static struct videobuf_queue_ops au0828_video_qops = {
>>> - .buf_setup = buffer_setup,
>>> - .buf_prepare = buffer_prepare,
>>> - .buf_queue = buffer_queue,
>>> - .buf_release = buffer_release,
>>> -};
>>> -
>>> -/* ------------------------------------------------------------------
>>> - V4L2 interface
>>> - ------------------------------------------------------------------*/
>>> -
>>> static int au0828_i2s_init(struct au0828_dev *dev)
>>> {
>>> /* Enable i2s mode */
>>> @@ -828,7 +746,7 @@ static int au0828_analog_stream_enable(struct au0828_dev *d)
>>> return 0;
>>> }
>>>
>>> -int au0828_analog_stream_disable(struct au0828_dev *d)
>>> +static int au0828_analog_stream_disable(struct au0828_dev *d)
>>> {
>>> dprintk(1, "au0828_analog_stream_disable called\n");
>>> au0828_writereg(d, AU0828_SENSORCTRL_100, 0x0);
>>> @@ -861,78 +779,141 @@ static int au0828_stream_interrupt(struct au0828_dev *dev)
>>> return 0;
>>> }
>>>
>>> -/*
>>> - * au0828_release_resources
>>> - * unregister v4l2 devices
>>> - */
>>> -void au0828_analog_unregister(struct au0828_dev *dev)
>>> +int au0828_start_analog_streaming(struct vb2_queue *vq, unsigned int count)
>>> {
>>> - dprintk(1, "au0828_release_resources called\n");
>>> - mutex_lock(&au0828_sysfs_lock);
>>> + struct au0828_dev *dev = vb2_get_drv_priv(vq);
>>> + int rc = 0;
>>>
>>> - if (dev->vdev)
>>> - video_unregister_device(dev->vdev);
>>> - if (dev->vbi_dev)
>>> - video_unregister_device(dev->vbi_dev);
>>> + dprintk(1, "au0828_start_analog_streaming called %d\n",
>>> + dev->streaming_users);
>>>
>>> - mutex_unlock(&au0828_sysfs_lock);
>>> -}
>>> + if (vq->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
>>> + dev->frame_count = 0;
>>> + else
>>> + dev->vbi_frame_count = 0;
>>> +
>>> + if (dev->streaming_users == 0) {
>>> + /* If we were doing ac97 instead of i2s, it would go here...*/
>>> + au0828_i2s_init(dev);
>>> + rc = au0828_init_isoc(dev, AU0828_ISO_PACKETS_PER_URB,
>>> + AU0828_MAX_ISO_BUFS, dev->max_pkt_size,
>>> + au0828_isoc_copy);
>>> + if (rc < 0) {
>>> + pr_info("au0828_init_isoc failed\n");
>>> + return rc;
>>> + }
>>>
>>> + if (vq->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
>>> + v4l2_device_call_all(&dev->v4l2_dev, 0, video,
>>> + s_stream, 1);
>>> + dev->vid_timeout_running = 1;
>>> + mod_timer(&dev->vid_timeout, jiffies + (HZ / 10));
>>> + } else if (vq->type == V4L2_BUF_TYPE_VBI_CAPTURE) {
>>> + dev->vbi_timeout_running = 1;
>>> + mod_timer(&dev->vbi_timeout, jiffies + (HZ / 10));
>>> + }
>>> + }
>>> + dev->streaming_users++;
>>> + return rc;
>>> +}
>>>
>>> -/* Usage lock check functions */
>>> -static int res_get(struct au0828_fh *fh, unsigned int bit)
>>> +static void au0828_stop_streaming(struct vb2_queue *vq)
>>> {
>>> - struct au0828_dev *dev = fh->dev;
>>> + struct au0828_dev *dev = vb2_get_drv_priv(vq);
>>> + struct au0828_dmaqueue *vidq = &dev->vidq;
>>> + unsigned long flags = 0;
>>> + int i;
>>>
>>> - if (fh->resources & bit)
>>> - /* have it already allocated */
>>> - return 1;
>>> + dprintk(1, "au0828_stop_streaming called %d\n", dev->streaming_users);
>>>
>>> - /* is it free? */
>>> - if (dev->resources & bit) {
>>> - /* no, someone else uses it */
>>> - return 0;
>>> + if (dev->streaming_users-- == 1)
>>> + au0828_uninit_isoc(dev);
>>> +
>>> + spin_lock_irqsave(&dev->slock, flags);
>>> + if (dev->isoc_ctl.buf != NULL) {
>>> + vb2_buffer_done(&dev->isoc_ctl.buf->vb, VB2_BUF_STATE_ERROR);
>>> + dev->isoc_ctl.buf = NULL;
>>> }
>>> - /* it's free, grab it */
>>> - fh->resources |= bit;
>>> - dev->resources |= bit;
>>> - dprintk(1, "res: get %d\n", bit);
>>> + while (!list_empty(&vidq->active)) {
>>> + struct au0828_buffer *buf;
>>>
>>> - return 1;
>>> -}
>>> + buf = list_entry(vidq->active.next, struct au0828_buffer, list);
>>> + vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
>>> + list_del(&buf->list);
>>> + }
>>>
>>> -static int res_check(struct au0828_fh *fh, unsigned int bit)
>>> -{
>>> - return fh->resources & bit;
>>> -}
>>> + v4l2_device_call_all(&dev->v4l2_dev, 0, video, s_stream, 0);
>>>
>>> -static int res_locked(struct au0828_dev *dev, unsigned int bit)
>>> -{
>>> - return dev->resources & bit;
>>> + for (i = 0; i < AU0828_MAX_INPUT; i++) {
>>> + if (AUVI_INPUT(i).audio_setup == NULL)
>>> + continue;
>>> + (AUVI_INPUT(i).audio_setup)(dev, 0);
>>> + }
>>> + spin_unlock_irqrestore(&dev->slock, flags);
>>> +
>>> + dev->vid_timeout_running = 0;
>>> + del_timer_sync(&dev->vid_timeout);
>>> }
>>>
>>> -static void res_free(struct au0828_fh *fh, unsigned int bits)
>>> +void au0828_stop_vbi_streaming(struct vb2_queue *vq)
>>> {
>>> - struct au0828_dev *dev = fh->dev;
>>> + struct au0828_dev *dev = vb2_get_drv_priv(vq);
>>> + struct au0828_dmaqueue *vbiq = &dev->vbiq;
>>> + unsigned long flags = 0;
>>> +
>>> + dprintk(1, "au0828_stop_vbi_streaming called %d\n",
>>> + dev->streaming_users);
>>> +
>>> + if (dev->streaming_users-- == 1)
>>> + au0828_uninit_isoc(dev);
>>>
>>> - BUG_ON((fh->resources & bits) != bits);
>>> + spin_lock_irqsave(&dev->slock, flags);
>>> + if (dev->isoc_ctl.vbi_buf != NULL) {
>>> + vb2_buffer_done(&dev->isoc_ctl.vbi_buf->vb,
>>> + VB2_BUF_STATE_ERROR);
>>> + dev->isoc_ctl.vbi_buf = NULL;
>>> + }
>>> + while (!list_empty(&vbiq->active)) {
>>> + struct au0828_buffer *buf;
>>> +
>>> + buf = list_entry(vbiq->active.next, struct au0828_buffer, list);
>>> + list_del(&buf->list);
>>> + vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
>>> + }
>>> + spin_unlock_irqrestore(&dev->slock, flags);
>>>
>>> - fh->resources &= ~bits;
>>> - dev->resources &= ~bits;
>>> - dprintk(1, "res: put %d\n", bits);
>>> + dev->vbi_timeout_running = 0;
>>> + del_timer_sync(&dev->vbi_timeout);
>>> }
>>>
>>> -static int get_ressource(struct au0828_fh *fh)
>>> +static struct vb2_ops au0828_video_qops = {
>>> + .queue_setup = queue_setup,
>>> + .buf_prepare = buffer_prepare,
>>> + .buf_queue = buffer_queue,
>>> + .start_streaming = au0828_start_analog_streaming,
>>> + .stop_streaming = au0828_stop_streaming,
>>> + .wait_prepare = vb2_ops_wait_prepare,
>>> + .wait_finish = vb2_ops_wait_finish,
>>> +};
>>> +
>>> +/* ------------------------------------------------------------------
>>> + V4L2 interface
>>> + ------------------------------------------------------------------*/
>>> +/*
>>> + * au0828_analog_unregister
>>> + * unregister v4l2 devices
>>> + */
>>> +void au0828_analog_unregister(struct au0828_dev *dev)
>>> {
>>> - switch (fh->type) {
>>> - case V4L2_BUF_TYPE_VIDEO_CAPTURE:
>>> - return AU0828_RESOURCE_VIDEO;
>>> - case V4L2_BUF_TYPE_VBI_CAPTURE:
>>> - return AU0828_RESOURCE_VBI;
>>> - default:
>>> - BUG();
>>> - return 0;
>>> - }
>>> + dprintk(1, "au0828_analog_unregister called\n");
>>> + mutex_lock(&au0828_sysfs_lock);
>>> +
>>> + if (dev->vdev)
>>> + video_unregister_device(dev->vdev);
>>> + if (dev->vbi_dev)
>>> + video_unregister_device(dev->vbi_dev);
>>> +
>>> + mutex_unlock(&au0828_sysfs_lock);
>>> }
>>>
>>> /* This function ensures that video frames continue to be delivered even if
>>> @@ -950,8 +931,8 @@ static void au0828_vid_buffer_timeout(unsigned long data)
>>>
>>> buf = dev->isoc_ctl.buf;
>>> if (buf != NULL) {
>>> - vid_data = videobuf_to_vmalloc(&buf->vb);
>>> - memset(vid_data, 0x00, buf->vb.size); /* Blank green frame */
>>> + vid_data = vb2_plane_vaddr(&buf->vb, 0);
>>> + memset(vid_data, 0x00, buf->length); /* Blank green frame */
>>> buffer_filled(dev, dma_q, buf);
>>> }
>>> get_next_buf(dma_q, &buf);
>>> @@ -974,8 +955,8 @@ static void au0828_vbi_buffer_timeout(unsigned long data)
>>>
>>> buf = dev->isoc_ctl.vbi_buf;
>>> if (buf != NULL) {
>>> - vbi_data = videobuf_to_vmalloc(&buf->vb);
>>> - memset(vbi_data, 0x00, buf->vb.size);
>>> + vbi_data = vb2_plane_vaddr(&buf->vb, 0);
>>> + memset(vbi_data, 0x00, buf->length);
>>> vbi_buffer_filled(dev, dma_q, buf);
>>> }
>>> vbi_get_next_buf(dma_q, &buf);
>>> @@ -985,105 +966,65 @@ static void au0828_vbi_buffer_timeout(unsigned long data)
>>> spin_unlock_irqrestore(&dev->slock, flags);
>>> }
>>>
>>> -
>>> static int au0828_v4l2_open(struct file *filp)
>>> {
>>> - int ret = 0;
>>> - struct video_device *vdev = video_devdata(filp);
>>> struct au0828_dev *dev = video_drvdata(filp);
>>> - struct au0828_fh *fh;
>>> - int type;
>>> -
>>> - switch (vdev->vfl_type) {
>>> - case VFL_TYPE_GRABBER:
>>> - type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
>>> - break;
>>> - case VFL_TYPE_VBI:
>>> - type = V4L2_BUF_TYPE_VBI_CAPTURE;
>>> - break;
>>> - default:
>>> - return -EINVAL;
>>> - }
>>> -
>>> - fh = kzalloc(sizeof(struct au0828_fh), GFP_KERNEL);
>>> - if (NULL == fh) {
>>> - dprintk(1, "Failed allocate au0828_fh struct!\n");
>>> - return -ENOMEM;
>>> - }
>>> + int ret = 0;
>>>
>> No need to assign it to zero.
>
> Yes. Looks like there are a few other routines that zero out
> ret. If you want to see all of those cleaned up, I can do a
> separate patch cleaning all these instances. If not I can send
> patch v4? Please let me know your preference.
>
No it needs to go in this patch itself for here.

>>
>>> - fh->type = type;
>>> - fh->dev = dev;
>>> - v4l2_fh_init(&fh->fh, vdev);
>>> - filp->private_data = fh;
>>> + dprintk(1,
>>> + "%s called std_set %d dev_state %d stream users %d users %d\n",
>>> + __func__, dev->std_set_in_tuner_core, dev->dev_state,
>>> + dev->streaming_users, dev->users);
>>>
>>> - if (mutex_lock_interruptible(&dev->lock)) {
>>> - kfree(fh);
>>> + if (mutex_lock_interruptible(&dev->lock))
>>> return -ERESTARTSYS;
>>> +
>>> + ret = v4l2_fh_open(filp);
>>> + if (ret) {
>>> + au0828_isocdbg("%s: v4l2_fh_open() returned error %d\n",
>>> + __func__, ret);
>>> + mutex_unlock(&dev->lock);
>>> + return ret;
>>> }
>>> +
>>> if (dev->users == 0) {
>>
>> you can use v4l2_fh_is_singular_file() and get rid of users member ?
>
> Please see Devin's response on this. I have been debugging the change
> I made to use v4l2_fh_is_singular_file() instead of users and seeing
> problem with reset stream and couldn't really figure out why until
> Devin explained it.
>
Agreed.

Thanks,
--Prabhakar Lad