diff options
Diffstat (limited to 'drivers/usb/gadget/function/uvc_video.c')
| -rw-r--r-- | drivers/usb/gadget/function/uvc_video.c | 130 |
1 files changed, 110 insertions, 20 deletions
diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index c3e8c48f46a9..164bdeb7f2a9 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -227,6 +227,10 @@ uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video, * Request handling */ +/* + * Callers must take care to hold req_lock when this function may be called + * from multiple threads. For example, when frames are streaming to the host. + */ static void uvc_video_free_request(struct uvc_request *ureq, struct usb_ep *ep) { @@ -271,9 +275,26 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req) struct uvc_request *ureq = req->context; struct uvc_video *video = ureq->video; struct uvc_video_queue *queue = &video->queue; - struct uvc_device *uvc = video->uvc; + struct uvc_buffer *last_buf; unsigned long flags; + spin_lock_irqsave(&video->req_lock, flags); + if (!video->is_enabled) { + /* + * When is_enabled is false, uvcg_video_disable() ensures + * that in-flight uvc_buffers are returned, so we can + * safely call free_request without worrying about + * last_buf. + */ + uvc_video_free_request(ureq, ep); + spin_unlock_irqrestore(&video->req_lock, flags); + return; + } + + last_buf = ureq->last_buf; + ureq->last_buf = NULL; + spin_unlock_irqrestore(&video->req_lock, flags); + switch (req->status) { case 0: break; @@ -295,17 +316,26 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req) uvcg_queue_cancel(queue, 0); } - if (ureq->last_buf) { - uvcg_complete_buffer(&video->queue, ureq->last_buf); - ureq->last_buf = NULL; + if (last_buf) { + spin_lock_irqsave(&queue->irqlock, flags); + uvcg_complete_buffer(queue, last_buf); + spin_unlock_irqrestore(&queue->irqlock, flags); } spin_lock_irqsave(&video->req_lock, flags); - list_add_tail(&req->list, &video->req_free); - spin_unlock_irqrestore(&video->req_lock, flags); - - if (uvc->state == UVC_STATE_STREAMING) + /* + * Video stream might have been disabled while we were + * processing the current usb_request. So make sure + * we're still streaming before queueing the usb_request + * back to req_free + */ + if (video->is_enabled) { + list_add_tail(&req->list, &video->req_free); queue_work(video->async_wq, &video->pump); + } else { + uvc_video_free_request(ureq, ep); + } + spin_unlock_irqrestore(&video->req_lock, flags); } static int @@ -392,20 +422,22 @@ static void uvcg_video_pump(struct work_struct *work) struct uvc_video_queue *queue = &video->queue; /* video->max_payload_size is only set when using bulk transfer */ bool is_bulk = video->max_payload_size; - struct uvc_device *uvc = video->uvc; struct usb_request *req = NULL; struct uvc_buffer *buf; unsigned long flags; bool buf_done; int ret; - while (uvc->state == UVC_STATE_STREAMING && video->ep->enabled) { + while (true) { + if (!video->ep->enabled) + return; + /* - * Retrieve the first available USB request, protected by the - * request lock. + * Check is_enabled and retrieve the first available USB + * request, protected by the request lock. */ spin_lock_irqsave(&video->req_lock, flags); - if (list_empty(&video->req_free)) { + if (!video->is_enabled || list_empty(&video->req_free)) { spin_unlock_irqrestore(&video->req_lock, flags); return; } @@ -487,9 +519,11 @@ static void uvcg_video_pump(struct work_struct *work) return; spin_lock_irqsave(&video->req_lock, flags); - list_add_tail(&req->list, &video->req_free); + if (video->is_enabled) + list_add_tail(&req->list, &video->req_free); + else + uvc_video_free_request(req->context, video->ep); spin_unlock_irqrestore(&video->req_lock, flags); - return; } /* @@ -498,7 +532,11 @@ static void uvcg_video_pump(struct work_struct *work) int uvcg_video_disable(struct uvc_video *video) { - struct uvc_request *ureq; + unsigned long flags; + struct list_head inflight_bufs; + struct usb_request *req, *temp; + struct uvc_buffer *buf, *btemp; + struct uvc_request *ureq, *utemp; if (video->ep == NULL) { uvcg_info(&video->uvc->func, @@ -506,15 +544,58 @@ uvcg_video_disable(struct uvc_video *video) return -ENODEV; } + INIT_LIST_HEAD(&inflight_bufs); + spin_lock_irqsave(&video->req_lock, flags); + video->is_enabled = false; + + /* + * Remove any in-flight buffers from the uvc_requests + * because we want to return them before cancelling the + * queue. This ensures that we aren't stuck waiting for + * all complete callbacks to come through before disabling + * vb2 queue. + */ + list_for_each_entry(ureq, &video->ureqs, list) { + if (ureq->last_buf) { + list_add_tail(&ureq->last_buf->queue, &inflight_bufs); + ureq->last_buf = NULL; + } + } + spin_unlock_irqrestore(&video->req_lock, flags); + cancel_work_sync(&video->pump); uvcg_queue_cancel(&video->queue, 0); - list_for_each_entry(ureq, &video->ureqs, list) { - if (ureq->req) - usb_ep_dequeue(video->ep, ureq->req); + spin_lock_irqsave(&video->req_lock, flags); + /* + * Remove all uvc_requests from ureqs with list_del_init + * This lets uvc_video_free_request correctly identify + * if the uvc_request is attached to a list or not when freeing + * memory. + */ + list_for_each_entry_safe(ureq, utemp, &video->ureqs, list) + list_del_init(&ureq->list); + + list_for_each_entry_safe(req, temp, &video->req_free, list) { + list_del(&req->list); + uvc_video_free_request(req->context, video->ep); } - uvc_video_free_requests(video); + INIT_LIST_HEAD(&video->ureqs); + INIT_LIST_HEAD(&video->req_free); + video->req_size = 0; + spin_unlock_irqrestore(&video->req_lock, flags); + + /* + * Return all the video buffers before disabling the queue. + */ + spin_lock_irqsave(&video->queue.irqlock, flags); + list_for_each_entry_safe(buf, btemp, &inflight_bufs, queue) { + list_del(&buf->queue); + uvcg_complete_buffer(&video->queue, buf); + } + spin_unlock_irqrestore(&video->queue.irqlock, flags); + uvcg_queue_enable(&video->queue, 0); return 0; } @@ -532,6 +613,14 @@ int uvcg_video_enable(struct uvc_video *video) return -ENODEV; } + /* + * Safe to access request related fields without req_lock because + * this is the only thread currently active, and no other + * request handling thread will become active until this function + * returns. + */ + video->is_enabled = true; + if ((ret = uvcg_queue_enable(&video->queue, 1)) < 0) return ret; @@ -557,6 +646,7 @@ int uvcg_video_enable(struct uvc_video *video) */ int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc) { + video->is_enabled = false; INIT_LIST_HEAD(&video->ureqs); INIT_LIST_HEAD(&video->req_free); spin_lock_init(&video->req_lock); |