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 <[email protected]> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
