urb completion callback is executed in host controllers interrupt
context. To keep preempt disable time short, add an ordered work-
queue. Associate a work_struct with each urb and queue work using it
on urb completion.
In uvc_uninit_video, usb_kill_urb and usb_free_urb are separated in
different loops so that workqueue can be destroyed without a lock.
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@xxxxxxxxx>
---
drivers/media/usb/uvc/uvc_video.c | 63 ++++++++++++++++++++++++++++++++-------
drivers/media/usb/uvc/uvcvideo.h | 9 +++++-
2 files changed, 60 insertions(+), 12 deletions(-)
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index f839654..943dbd6 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -1317,9 +1317,23 @@ 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_work *uw = urb->context;
+ struct uvc_streaming *stream = uw->stream;
+ /* stream->urb_wq can be set to NULL without lock */
+ struct workqueue_struct *wq = stream->urb_wq;
+
+ if (wq)
+ queue_work(wq, &uw->work);
+}
+
+static void uvc_video_complete_work(struct work_struct *work)
+{
+ struct uvc_urb_work *uw = container_of(work, struct uvc_urb_work,
+ work);
+ struct urb *urb = uw->urb;
+ struct uvc_streaming *stream = uw->stream;
struct uvc_video_queue *queue = &stream->queue;
struct uvc_buffer *buf = NULL;
unsigned long flags;
@@ -1445,17 +1459,34 @@ static void uvc_uninit_video(struct uvc_streaming *stream, int free_buffers)
{
struct urb *urb;
unsigned int i;
+ struct workqueue_struct *wq;
uvc_video_stats_stop(stream);
+ /* Kill all URB first so that urb_wq can be destroyed without a lock */
for (i = 0; i < UVC_URBS; ++i) {
- urb = stream->urb[i];
+ urb = stream->uw[i].urb;
if (urb == NULL)
continue;
usb_kill_urb(urb);
+ }
+
+ if (stream->urb_wq) {
+ wq = stream->urb_wq;
+ /* Since all URBs are killed set urb_wq to NULL */
+ stream->urb_wq = NULL;
+ flush_workqueue(wq);
+ destroy_workqueue(wq);
+ }
+
+ for (i = 0; i < UVC_URBS; ++i) {
+ urb = stream->uw[i].urb;
+ if (urb == NULL)
+ continue;
+
usb_free_urb(urb);
- stream->urb[i] = NULL;
+ stream->uw[i].urb = NULL;
}
if (free_buffers)
@@ -1514,7 +1545,7 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream,
}
urb->dev = stream->dev->udev;
- urb->context = stream;
+ urb->context = &stream->uw[i];
urb->pipe = usb_rcvisocpipe(stream->dev->udev,
ep->desc.bEndpointAddress);
#ifndef CONFIG_DMA_NONCOHERENT
@@ -1525,7 +1556,7 @@ 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 +1565,9 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream,
urb->iso_frame_desc[j].length = psize;
}
- stream->urb[i] = urb;
+ stream->uw[i].urb = urb;
+ stream->uw[i].stream = stream;
+ INIT_WORK(&stream->uw[i].work, uvc_video_complete_work);
}
return 0;
@@ -1580,14 +1613,16 @@ 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->uw[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->uw[i].urb = urb;
+ stream->uw[i].stream = stream;
+ INIT_WORK(&stream->uw[i].work, uvc_video_complete_work);
}
return 0;
@@ -1676,9 +1711,15 @@ static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
if (ret < 0)
return ret;
+ stream->urb_wq = alloc_ordered_workqueue(stream->dev->name, 0);
+ if (!stream->urb_wq) {
+ uvc_printk(KERN_ERR, "Workqueue allocation failed\n");
+ return -ENOMEM;
+ }
+
/* Submit the URBs. */
for (i = 0; i < UVC_URBS; ++i) {
- ret = usb_submit_urb(stream->urb[i], gfp_flags);
+ ret = usb_submit_urb(stream->uw[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..e2c0617b 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -440,6 +440,12 @@ struct uvc_stats_stream {
unsigned int max_sof; /* Maximum STC.SOF value */
};
+struct uvc_urb_work {
+ struct urb *urb;
+ struct uvc_streaming *stream;
+ struct work_struct work;
+};
+
struct uvc_streaming {
struct list_head list;
struct uvc_device *dev;
@@ -482,7 +488,8 @@ struct uvc_streaming {
__u32 max_payload_size;
} bulk;
- struct urb *urb[UVC_URBS];
+ struct workqueue_struct *urb_wq;
+ struct uvc_urb_work uw[UVC_URBS];
char *urb_buffer[UVC_URBS];
dma_addr_t urb_dma[UVC_URBS];
unsigned int urb_size;
--
2.3.3
--
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