From: Hans de Goede <hdegoede@redhat.com>
To: Mian Yousaf Kaukab <yousaf.kaukab@intel.com>,
laurent.pinchart@ideasonboard.com, linux-media@vger.kernel.org
Cc: mchehab@osg.samsung.com, linux-usb@vger.kernel.org
Subject: Re: [PATCH v1] media: uvcvideo: handle urb completion in a work queue
Date: Tue, 8 Sep 2015 14:53:34 +0200 [thread overview]
Message-ID: <55EEDA4E.50504@redhat.com> (raw)
In-Reply-To: <1441643029-25341-1-git-send-email-yousaf.kaukab@intel.com>
Hi,
On 09/07/2015 06:23 PM, Mian Yousaf Kaukab wrote:
> urb completion callback is executed in host controllers interrupt
> context. To keep preempt disable time short, add urbs to a list on
> completion and schedule work to process the list.
>
> Moreover, save timestamp and sof number in the urb completion callback
> to avoid any delays.
Erm, I thought that we had already moved to using threaded interrupt
handling for the urb completion a while (1-2 years ?) back. Is this then
still needed ?
Regards,
Hans
>
> Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@intel.com>
> ---
> History:
> v1:
> - Use global work queue instead of creating ordered queue.
> - Add completed urbs to a list and process all on the list when work
> is scheduled
> - Save timestamp and sof number in urb completion callback and use
> in uvc_video_clock_decode() and uvc_video_decode_start()
> - Fix race between usb_submit_urb() from uvc_video_complete() and
> usb_kill_urb() from uvc_uninit_video()
>
> drivers/media/usb/uvc/uvc_isight.c | 3 +-
> drivers/media/usb/uvc/uvc_video.c | 132 +++++++++++++++++++++++++++----------
> drivers/media/usb/uvc/uvcvideo.h | 17 ++++-
> 3 files changed, 113 insertions(+), 39 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_isight.c b/drivers/media/usb/uvc/uvc_isight.c
> index 8510e725..7f93d09 100644
> --- a/drivers/media/usb/uvc/uvc_isight.c
> +++ b/drivers/media/usb/uvc/uvc_isight.c
> @@ -99,9 +99,10 @@ static int isight_decode(struct uvc_video_queue *queue, struct uvc_buffer *buf,
> return 0;
> }
>
> -void uvc_video_decode_isight(struct urb *urb, struct uvc_streaming *stream,
> +void uvc_video_decode_isight(struct uvc_urb *uu, struct uvc_streaming *stream,
> struct uvc_buffer *buf)
> {
> + struct urb *urb = uu->urb;
> int ret, i;
>
> for (i = 0; i < urb->number_of_packets; ++i) {
> diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
> index f839654..71354ec 100644
> --- a/drivers/media/usb/uvc/uvc_video.c
> +++ b/drivers/media/usb/uvc/uvc_video.c
> @@ -379,15 +379,14 @@ static inline void uvc_video_get_ts(struct timespec *ts)
>
> static void
> uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
> - const __u8 *data, int len)
> + const __u8 *data, int len, u16 host_sof,
> + struct timespec *ts)
> {
> struct uvc_clock_sample *sample;
> unsigned int header_size;
> bool has_pts = false;
> bool has_scr = false;
> unsigned long flags;
> - struct timespec ts;
> - u16 host_sof;
> u16 dev_sof;
>
> switch (data[1] & (UVC_STREAM_PTS | UVC_STREAM_SCR)) {
> @@ -435,9 +434,6 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
>
> stream->clock.last_sof = dev_sof;
>
> - host_sof = usb_get_current_frame_number(stream->dev->udev);
> - uvc_video_get_ts(&ts);
> -
> /* The UVC specification allows device implementations that can't obtain
> * the USB frame number to keep their own frame counters as long as they
> * match the size and frequency of the frame number associated with USB
> @@ -473,7 +469,7 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
> sample->dev_stc = get_unaligned_le32(&data[header_size - 6]);
> sample->dev_sof = dev_sof;
> sample->host_sof = host_sof;
> - sample->host_ts = ts;
> + sample->host_ts = *ts;
>
> /* Update the sliding window head and count. */
> stream->clock.head = (stream->clock.head + 1) % stream->clock.size;
> @@ -964,7 +960,8 @@ static void uvc_video_stats_stop(struct uvc_streaming *stream)
> * uvc_video_decode_end will never be called with a NULL buffer.
> */
> static int uvc_video_decode_start(struct uvc_streaming *stream,
> - struct uvc_buffer *buf, const __u8 *data, int len)
> + struct uvc_buffer *buf, const __u8 *data, int len,
> + u16 host_sof, struct timespec *ts)
> {
> __u8 fid;
>
> @@ -989,7 +986,7 @@ static int uvc_video_decode_start(struct uvc_streaming *stream,
> uvc_video_stats_update(stream);
> }
>
> - uvc_video_clock_decode(stream, buf, data, len);
> + uvc_video_clock_decode(stream, buf, data, len, host_sof, ts);
> uvc_video_stats_decode(stream, data, len);
>
> /* Store the payload FID bit and return immediately when the buffer is
> @@ -1016,8 +1013,6 @@ static int uvc_video_decode_start(struct uvc_streaming *stream,
> * when the EOF bit is set to force synchronisation on the next packet.
> */
> if (buf->state != UVC_BUF_STATE_ACTIVE) {
> - struct timespec ts;
> -
> if (fid == stream->last_fid) {
> uvc_trace(UVC_TRACE_FRAME, "Dropping payload (out of "
> "sync).\n");
> @@ -1027,13 +1022,11 @@ static int uvc_video_decode_start(struct uvc_streaming *stream,
> return -ENODATA;
> }
>
> - uvc_video_get_ts(&ts);
> -
> buf->buf.v4l2_buf.field = V4L2_FIELD_NONE;
> buf->buf.v4l2_buf.sequence = stream->sequence;
> - buf->buf.v4l2_buf.timestamp.tv_sec = ts.tv_sec;
> + buf->buf.v4l2_buf.timestamp.tv_sec = ts->tv_sec;
> buf->buf.v4l2_buf.timestamp.tv_usec =
> - ts.tv_nsec / NSEC_PER_USEC;
> + ts->tv_nsec / NSEC_PER_USEC;
>
> /* TODO: Handle PTS and SCR. */
> buf->state = UVC_BUF_STATE_ACTIVE;
> @@ -1160,9 +1153,10 @@ static void uvc_video_validate_buffer(const struct uvc_streaming *stream,
> /*
> * Completion handler for video URBs.
> */
> -static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
> - struct uvc_buffer *buf)
> +static void uvc_video_decode_isoc(struct uvc_urb *uu,
> + struct uvc_streaming *stream, struct uvc_buffer *buf)
> {
> + struct urb *urb = uu->urb;
> u8 *mem;
> int ret, i;
>
> @@ -1180,7 +1174,8 @@ static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
> mem = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
> do {
> ret = uvc_video_decode_start(stream, buf, mem,
> - urb->iso_frame_desc[i].actual_length);
> + urb->iso_frame_desc[i].actual_length, uu->sof,
> + &uu->ts);
> if (ret == -EAGAIN) {
> uvc_video_validate_buffer(stream, buf);
> buf = uvc_queue_next_buffer(&stream->queue,
> @@ -1206,9 +1201,10 @@ static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
> }
> }
>
> -static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
> - struct uvc_buffer *buf)
> +static void uvc_video_decode_bulk(struct uvc_urb *uu,
> + struct uvc_streaming *stream, struct uvc_buffer *buf)
> {
> + struct urb *urb = uu->urb;
> u8 *mem;
> int len, ret;
>
> @@ -1228,7 +1224,8 @@ static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
> */
> if (stream->bulk.header_size == 0 && !stream->bulk.skip_payload) {
> do {
> - ret = uvc_video_decode_start(stream, buf, mem, len);
> + ret = uvc_video_decode_start(stream, buf, mem, len,
> + uu->sof, &uu->ts);
> if (ret == -EAGAIN)
> buf = uvc_queue_next_buffer(&stream->queue,
> buf);
> @@ -1274,9 +1271,10 @@ static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
> }
> }
>
> -static void uvc_video_encode_bulk(struct urb *urb, struct uvc_streaming *stream,
> - struct uvc_buffer *buf)
> +static void uvc_video_encode_bulk(struct uvc_urb *uu,
> + struct uvc_streaming *stream, struct uvc_buffer *buf)
> {
> + struct urb *urb = uu->urb;
> u8 *mem = urb->transfer_buffer;
> int len = stream->urb_size, ret;
>
> @@ -1317,9 +1315,26 @@ static void uvc_video_encode_bulk(struct urb *urb, struct uvc_streaming *stream,
> urb->transfer_buffer_length = stream->urb_size - len;
> }
>
> -static void uvc_video_complete(struct urb *urb)
> +static void uvc_urb_complete(struct urb *urb)
> {
> - struct uvc_streaming *stream = urb->context;
> + struct uvc_urb *uu = urb->context;
> + struct uvc_streaming *stream = uu->stream;
> + unsigned long flags;
> +
> + uu->sof = usb_get_current_frame_number(stream->dev->udev);
> + uvc_video_get_ts(&uu->ts);
> +
> + spin_lock_irqsave(&stream->urb_list_lock, flags);
> + list_add_tail(&urb->urb_list, &stream->urb_complete_list);
> + spin_unlock_irqrestore(&stream->urb_list_lock, flags);
> +
> + schedule_work(&stream->urb_work);
> +}
> +
> +static void uvc_video_complete(struct uvc_urb *uu)
> +{
> + struct urb *urb = uu->urb;
> + struct uvc_streaming *stream = uu->stream;
> struct uvc_video_queue *queue = &stream->queue;
> struct uvc_buffer *buf = NULL;
> unsigned long flags;
> @@ -1349,7 +1364,10 @@ static void uvc_video_complete(struct urb *urb)
> queue);
> spin_unlock_irqrestore(&queue->irqlock, flags);
>
> - stream->decode(urb, stream, buf);
> + stream->decode(uu, stream, buf);
> +
> + if (stream->stop)
> + return;
>
> if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
> uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n",
> @@ -1357,6 +1375,29 @@ static void uvc_video_complete(struct urb *urb)
> }
> }
>
> +static void uvc_video_complete_work(struct work_struct *work)
> +{
> + struct uvc_streaming *stream = container_of(work, struct uvc_streaming,
> + urb_work);
> + struct urb *urb;
> + unsigned long flags;
> + int i;
> +
> + for (i = 0; i < UVC_URBS; i++) {
> + spin_lock_irqsave(&stream->urb_list_lock, flags);
> + if (list_empty(&stream->urb_complete_list)) {
> + spin_unlock_irqrestore(&stream->urb_list_lock, flags);
> + return;
> + }
> + urb = list_first_entry(&stream->urb_complete_list,
> + struct urb, urb_list);
> + list_del(&urb->urb_list);
> + spin_unlock_irqrestore(&stream->urb_list_lock, flags);
> +
> + uvc_video_complete(urb->context);
> + }
> +}
> +
> /*
> * Free transfer buffers.
> */
> @@ -1448,14 +1489,28 @@ static void uvc_uninit_video(struct uvc_streaming *stream, int free_buffers)
>
> uvc_video_stats_stop(stream);
>
> + /* set stop and make sure no urb is being submitted.*/
> + stream->stop = true;
> + flush_work(&stream->urb_work);
> +
> for (i = 0; i < UVC_URBS; ++i) {
> - urb = stream->urb[i];
> + urb = stream->uvc_urb[i].urb;
> if (urb == NULL)
> continue;
>
> usb_kill_urb(urb);
> + }
> +
> + /* Finish all kill callbacks */
> + flush_work(&stream->urb_work);
> +
> + for (i = 0; i < UVC_URBS; ++i) {
> + urb = stream->uvc_urb[i].urb;
> + if (urb == NULL)
> + continue;
> +
> usb_free_urb(urb);
> - stream->urb[i] = NULL;
> + stream->uvc_urb[i].urb = NULL;
> }
>
> if (free_buffers)
> @@ -1514,7 +1569,7 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream,
> }
>
> urb->dev = stream->dev->udev;
> - urb->context = stream;
> + urb->context = &stream->uvc_urb[i];
> urb->pipe = usb_rcvisocpipe(stream->dev->udev,
> ep->desc.bEndpointAddress);
> #ifndef CONFIG_DMA_NONCOHERENT
> @@ -1525,7 +1580,7 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream,
> #endif
> urb->interval = ep->desc.bInterval;
> urb->transfer_buffer = stream->urb_buffer[i];
> - urb->complete = uvc_video_complete;
> + urb->complete = uvc_urb_complete;
> urb->number_of_packets = npackets;
> urb->transfer_buffer_length = size;
>
> @@ -1534,7 +1589,8 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream,
> urb->iso_frame_desc[j].length = psize;
> }
>
> - stream->urb[i] = urb;
> + stream->uvc_urb[i].urb = urb;
> + stream->uvc_urb[i].stream = stream;
> }
>
> return 0;
> @@ -1580,14 +1636,15 @@ static int uvc_init_video_bulk(struct uvc_streaming *stream,
> }
>
> usb_fill_bulk_urb(urb, stream->dev->udev, pipe,
> - stream->urb_buffer[i], size, uvc_video_complete,
> - stream);
> + stream->urb_buffer[i], size, uvc_urb_complete,
> + &stream->uvc_urb[i]);
> #ifndef CONFIG_DMA_NONCOHERENT
> urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
> urb->transfer_dma = stream->urb_dma[i];
> #endif
>
> - stream->urb[i] = urb;
> + stream->uvc_urb[i].urb = urb;
> + stream->uvc_urb[i].stream = stream;
> }
>
> return 0;
> @@ -1611,6 +1668,11 @@ static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
>
> uvc_video_stats_start(stream);
>
> + INIT_WORK(&stream->urb_work, uvc_video_complete_work);
> + INIT_LIST_HEAD(&stream->urb_complete_list);
> + spin_lock_init(&stream->urb_list_lock);
> + stream->stop = false;
> +
> if (intf->num_altsetting > 1) {
> struct usb_host_endpoint *best_ep = NULL;
> unsigned int best_psize = UINT_MAX;
> @@ -1678,7 +1740,7 @@ static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
>
> /* Submit the URBs. */
> for (i = 0; i < UVC_URBS; ++i) {
> - ret = usb_submit_urb(stream->urb[i], gfp_flags);
> + ret = usb_submit_urb(stream->uvc_urb[i].urb, gfp_flags);
> if (ret < 0) {
> uvc_printk(KERN_ERR, "Failed to submit URB %u "
> "(%d).\n", i, ret);
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index 816dd1a..b73c0ab 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -440,6 +440,13 @@ struct uvc_stats_stream {
> unsigned int max_sof; /* Maximum STC.SOF value */
> };
>
> +struct uvc_urb {
> + struct urb *urb;
> + struct uvc_streaming *stream;
> + struct timespec ts;
> + u16 sof;
> +};
> +
> struct uvc_streaming {
> struct list_head list;
> struct uvc_device *dev;
> @@ -470,7 +477,7 @@ struct uvc_streaming {
> /* Buffers queue. */
> unsigned int frozen : 1;
> struct uvc_video_queue queue;
> - void (*decode) (struct urb *urb, struct uvc_streaming *video,
> + void (*decode)(struct uvc_urb *uu, struct uvc_streaming *video,
> struct uvc_buffer *buf);
>
> /* Context data used by the bulk completion handler. */
> @@ -482,7 +489,11 @@ struct uvc_streaming {
> __u32 max_payload_size;
> } bulk;
>
> - struct urb *urb[UVC_URBS];
> + bool stop;
> + spinlock_t urb_list_lock;
> + struct list_head urb_complete_list;
> + struct work_struct urb_work;
> + struct uvc_urb uvc_urb[UVC_URBS];
> char *urb_buffer[UVC_URBS];
> dma_addr_t urb_dma[UVC_URBS];
> unsigned int urb_size;
> @@ -728,7 +739,7 @@ extern struct usb_host_endpoint *uvc_find_endpoint(
> struct usb_host_interface *alts, __u8 epaddr);
>
> /* Quirks support */
> -void uvc_video_decode_isight(struct urb *urb, struct uvc_streaming *stream,
> +void uvc_video_decode_isight(struct uvc_urb *uu, struct uvc_streaming *stream,
> struct uvc_buffer *buf);
>
> /* debugfs and statistics */
>
next prev parent reply other threads:[~2015-09-08 12:53 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-07 16:23 [PATCH v1] media: uvcvideo: handle urb completion in a work queue Mian Yousaf Kaukab
2015-09-08 8:58 ` Oliver Neukum
2015-09-08 12:53 ` Hans de Goede [this message]
2015-09-08 14:36 ` Alan Stern
2015-09-09 8:30 ` Hans de Goede
2015-09-09 8:43 ` Laurent Pinchart
2015-09-09 15:14 ` Alan Stern
2015-09-09 16:02 ` Laurent Pinchart
2015-09-09 16:29 ` Alan Stern
2015-09-10 8:00 ` Kaukab, Yousaf
2015-09-09 14:42 ` Alan Stern
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