From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:51218 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754503AbbIHMxh (ORCPT ); Tue, 8 Sep 2015 08:53:37 -0400 Subject: Re: [PATCH v1] media: uvcvideo: handle urb completion in a work queue To: Mian Yousaf Kaukab , laurent.pinchart@ideasonboard.com, linux-media@vger.kernel.org References: <1441643029-25341-1-git-send-email-yousaf.kaukab@intel.com> Cc: mchehab@osg.samsung.com, linux-usb@vger.kernel.org From: Hans de Goede Message-ID: <55EEDA4E.50504@redhat.com> Date: Tue, 8 Sep 2015 14:53:34 +0200 MIME-Version: 1.0 In-Reply-To: <1441643029-25341-1-git-send-email-yousaf.kaukab@intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: 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 > --- > 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 */ >