diff options
Diffstat (limited to 'drivers/usb/gadget/function/uvc_video.c')
-rw-r--r-- | drivers/usb/gadget/function/uvc_video.c | 453 |
1 files changed, 344 insertions, 109 deletions
diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index 91af3b1ef0..53e4cd81ea 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -35,6 +35,9 @@ uvc_video_encode_header(struct uvc_video *video, struct uvc_buffer *buf, data[1] = UVC_STREAM_EOH | video->fid; + if (video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE) + data[1] |= UVC_STREAM_ERR; + if (video->queue.buf_used == 0 && ts.tv_sec) { /* dwClockFrequency is 48 MHz */ u32 pts = ((u64)ts.tv_sec * USEC_PER_SEC + ts.tv_nsec / NSEC_PER_USEC) * 48; @@ -227,6 +230,28 @@ 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) +{ + sg_free_table(&ureq->sgt); + if (ureq->req && ep) { + usb_ep_free_request(ep, ureq->req); + ureq->req = NULL; + } + + kfree(ureq->req_buffer); + ureq->req_buffer = NULL; + + if (!list_empty(&ureq->list)) + list_del_init(&ureq->list); + + kfree(ureq); +} + static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req) { int ret; @@ -247,14 +272,127 @@ static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req) return ret; } +/* This function must be called with video->req_lock held. */ +static int uvcg_video_usb_req_queue(struct uvc_video *video, + struct usb_request *req, bool queue_to_ep) +{ + bool is_bulk = video->max_payload_size; + struct list_head *list = NULL; + + if (!video->is_enabled) + return -ENODEV; + + if (queue_to_ep) { + struct uvc_request *ureq = req->context; + /* + * With USB3 handling more requests at a higher speed, we can't + * afford to generate an interrupt for every request. Decide to + * interrupt: + * + * - When no more requests are available in the free queue, as + * this may be our last chance to refill the endpoint's + * request queue. + * + * - When this is request is the last request for the video + * buffer, as we want to start sending the next video buffer + * ASAP in case it doesn't get started already in the next + * iteration of this loop. + * + * - Four times over the length of the requests queue (as + * indicated by video->uvc_num_requests), as a trade-off + * between latency and interrupt load. + */ + if (list_empty(&video->req_free) || ureq->last_buf || + !(video->req_int_count % + DIV_ROUND_UP(video->uvc_num_requests, 4))) { + video->req_int_count = 0; + req->no_interrupt = 0; + } else { + req->no_interrupt = 1; + } + video->req_int_count++; + return uvcg_video_ep_queue(video, req); + } + /* + * If we're not queuing to the ep, for isoc we're queuing + * to the req_ready list, otherwise req_free. + */ + list = is_bulk ? &video->req_free : &video->req_ready; + list_add_tail(&req->list, list); + return 0; +} + +/* + * Must only be called from uvcg_video_enable - since after that we only want to + * queue requests to the endpoint from the uvc_video_complete complete handler. + * This function is needed in order to 'kick start' the flow of requests from + * gadget driver to the usb controller. + */ +static void uvc_video_ep_queue_initial_requests(struct uvc_video *video) +{ + struct usb_request *req = NULL; + unsigned long flags = 0; + unsigned int count = 0; + int ret = 0; + + /* + * We only queue half of the free list since we still want to have + * some free usb_requests in the free list for the video_pump async_wq + * thread to encode uvc buffers into. Otherwise we could get into a + * situation where the free list does not have any usb requests to + * encode into - we always end up queueing 0 length requests to the + * end point. + */ + unsigned int half_list_size = video->uvc_num_requests / 2; + + spin_lock_irqsave(&video->req_lock, flags); + /* + * Take these requests off the free list and queue them all to the + * endpoint. Since we queue 0 length requests with the req_lock held, + * there isn't any 'data' race involved here with the complete handler. + */ + while (count < half_list_size) { + req = list_first_entry(&video->req_free, struct usb_request, + list); + list_del(&req->list); + req->length = 0; + ret = uvcg_video_ep_queue(video, req); + if (ret < 0) { + uvcg_queue_cancel(&video->queue, 0); + break; + } + count++; + } + spin_unlock_irqrestore(&video->req_lock, flags); +} + static void 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; + bool is_bulk = video->max_payload_size; + int ret = 0; + + 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: @@ -277,44 +415,85 @@ 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); + /* + * 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) { + /* + * Here we check whether any request is available in the ready + * list. If it is, queue it to the ep and add the current + * usb_request to the req_free list - for video_pump to fill in. + * Otherwise, just use the current usb_request to queue a 0 + * length request to the ep. Since we always add to the req_free + * list if we dequeue from the ready list, there will never + * be a situation where the req_free list is completely out of + * requests and cannot recover. + */ + struct usb_request *to_queue = req; + + to_queue->length = 0; + if (!list_empty(&video->req_ready)) { + to_queue = list_first_entry(&video->req_ready, + struct usb_request, list); + list_del(&to_queue->list); + list_add_tail(&req->list, &video->req_free); + /* + * Queue work to the wq as well since it is possible that a + * buffer may not have been completely encoded with the set of + * in-flight usb requests for whih the complete callbacks are + * firing. + * In that case, if we do not queue work to the worker thread, + * the buffer will never be marked as complete - and therefore + * not be returned to userpsace. As a result, + * dequeue -> queue -> dequeue flow of uvc buffers will not + * happen. + */ + queue_work(video->async_wq, &video->pump); + } + /* + * Queue to the endpoint. The actual queueing to ep will + * only happen on one thread - the async_wq for bulk endpoints + * and this thread for isoc endpoints. + */ + ret = uvcg_video_usb_req_queue(video, to_queue, !is_bulk); + if (ret < 0) { + /* + * Endpoint error, but the stream is still enabled. + * Put request back in req_free for it to be cleaned + * up later. + */ + list_add_tail(&to_queue->list, &video->req_free); + } + } else { + uvc_video_free_request(ureq, ep); + ret = 0; + } spin_unlock_irqrestore(&video->req_lock, flags); - - if (uvc->state == UVC_STATE_STREAMING) - queue_work(video->async_wq, &video->pump); + if (ret < 0) + uvcg_queue_cancel(queue, 0); } static int uvc_video_free_requests(struct uvc_video *video) { - unsigned int i; - - if (video->ureq) { - for (i = 0; i < video->uvc_num_requests; ++i) { - sg_free_table(&video->ureq[i].sgt); + struct uvc_request *ureq, *temp; - if (video->ureq[i].req) { - usb_ep_free_request(video->ep, video->ureq[i].req); - video->ureq[i].req = NULL; - } - - if (video->ureq[i].req_buffer) { - kfree(video->ureq[i].req_buffer); - video->ureq[i].req_buffer = NULL; - } - } - - kfree(video->ureq); - video->ureq = NULL; - } + list_for_each_entry_safe(ureq, temp, &video->ureqs, list) + uvc_video_free_request(ureq, video->ep); + INIT_LIST_HEAD(&video->ureqs); INIT_LIST_HEAD(&video->req_free); + INIT_LIST_HEAD(&video->req_ready); video->req_size = 0; return 0; } @@ -322,6 +501,7 @@ uvc_video_free_requests(struct uvc_video *video) static int uvc_video_alloc_requests(struct uvc_video *video) { + struct uvc_request *ureq; unsigned int req_size; unsigned int i; int ret = -ENOMEM; @@ -332,29 +512,33 @@ uvc_video_alloc_requests(struct uvc_video *video) * max_t(unsigned int, video->ep->maxburst, 1) * (video->ep->mult); - video->ureq = kcalloc(video->uvc_num_requests, sizeof(struct uvc_request), GFP_KERNEL); - if (video->ureq == NULL) - return -ENOMEM; + for (i = 0; i < video->uvc_num_requests; i++) { + ureq = kzalloc(sizeof(struct uvc_request), GFP_KERNEL); + if (ureq == NULL) + goto error; + + INIT_LIST_HEAD(&ureq->list); - for (i = 0; i < video->uvc_num_requests; ++i) { - video->ureq[i].req_buffer = kmalloc(req_size, GFP_KERNEL); - if (video->ureq[i].req_buffer == NULL) + list_add_tail(&ureq->list, &video->ureqs); + + ureq->req_buffer = kmalloc(req_size, GFP_KERNEL); + if (ureq->req_buffer == NULL) goto error; - video->ureq[i].req = usb_ep_alloc_request(video->ep, GFP_KERNEL); - if (video->ureq[i].req == NULL) + ureq->req = usb_ep_alloc_request(video->ep, GFP_KERNEL); + if (ureq->req == NULL) goto error; - video->ureq[i].req->buf = video->ureq[i].req_buffer; - video->ureq[i].req->length = 0; - video->ureq[i].req->complete = uvc_video_complete; - video->ureq[i].req->context = &video->ureq[i]; - video->ureq[i].video = video; - video->ureq[i].last_buf = NULL; + ureq->req->buf = ureq->req_buffer; + ureq->req->length = 0; + ureq->req->complete = uvc_video_complete; + ureq->req->context = ureq; + ureq->video = video; + ureq->last_buf = NULL; - list_add_tail(&video->ureq[i].req->list, &video->req_free); + list_add_tail(&ureq->req->list, &video->req_free); /* req_size/PAGE_SIZE + 1 for overruns and + 1 for header */ - sg_alloc_table(&video->ureq[i].sgt, + sg_alloc_table(&ureq->sgt, DIV_ROUND_UP(req_size - UVCG_REQUEST_HEADER_LEN, PAGE_SIZE) + 2, GFP_KERNEL); } @@ -387,16 +571,18 @@ static void uvcg_video_pump(struct work_struct *work) struct usb_request *req = NULL; struct uvc_buffer *buf; unsigned long flags; - bool buf_done; - int ret; + int ret = 0; + + while (true) { + if (!video->ep->enabled) + return; - while (video->ep->enabled) { /* - * 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; } @@ -411,19 +597,7 @@ static void uvcg_video_pump(struct work_struct *work) */ spin_lock_irqsave(&queue->irqlock, flags); buf = uvcg_queue_head(queue); - - if (buf != NULL) { - video->encode(req, video, buf); - buf_done = buf->state == UVC_BUF_STATE_DONE; - } else if (!(queue->flags & UVC_QUEUE_DISCONNECTED) && !is_bulk) { - /* - * No video buffer available; the queue is still connected and - * we're transferring over ISOC. Queue a 0 length request to - * prevent missed ISOC transfers. - */ - req->length = 0; - buf_done = false; - } else { + if (!buf) { /* * Either the queue has been disconnected or no video buffer * available for bulk transfer. Either way, stop processing @@ -433,82 +607,140 @@ static void uvcg_video_pump(struct work_struct *work) break; } - /* - * With USB3 handling more requests at a higher speed, we can't - * afford to generate an interrupt for every request. Decide to - * interrupt: - * - * - When no more requests are available in the free queue, as - * this may be our last chance to refill the endpoint's - * request queue. - * - * - When this is request is the last request for the video - * buffer, as we want to start sending the next video buffer - * ASAP in case it doesn't get started already in the next - * iteration of this loop. - * - * - Four times over the length of the requests queue (as - * indicated by video->uvc_num_requests), as a trade-off - * between latency and interrupt load. - */ - if (list_empty(&video->req_free) || buf_done || - !(video->req_int_count % - DIV_ROUND_UP(video->uvc_num_requests, 4))) { - video->req_int_count = 0; - req->no_interrupt = 0; - } else { - req->no_interrupt = 1; - } + video->encode(req, video, buf); - /* Queue the USB request */ - ret = uvcg_video_ep_queue(video, req); spin_unlock_irqrestore(&queue->irqlock, flags); + spin_lock_irqsave(&video->req_lock, flags); + /* For bulk end points we queue from the worker thread + * since we would preferably not want to wait on requests + * to be ready, in the uvcg_video_complete() handler. + * For isoc endpoints we add the request to the ready list + * and only queue it to the endpoint from the complete handler. + */ + ret = uvcg_video_usb_req_queue(video, req, is_bulk); + spin_unlock_irqrestore(&video->req_lock, flags); + if (ret < 0) { uvcg_queue_cancel(queue, 0); break; } - /* Endpoint now owns the request */ + /* The request is owned by the endpoint / ready list. */ req = NULL; - video->req_int_count++; } if (!req) 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; } /* - * Enable or disable the video stream. + * Disable the video stream */ -int uvcg_video_enable(struct uvc_video *video, int enable) +int +uvcg_video_disable(struct uvc_video *video) { - unsigned int i; - int ret; + 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, - "Video enable failed, device is uninitialized.\n"); + "Video disable failed, device is uninitialized.\n"); return -ENODEV; } - if (!enable) { - cancel_work_sync(&video->pump); - uvcg_queue_cancel(&video->queue, 0); + 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); + + 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); + } + + list_for_each_entry_safe(req, temp, &video->req_ready, list) { + list_del(&req->list); + uvc_video_free_request(req->context, video->ep); + } - for (i = 0; i < video->uvc_num_requests; ++i) - if (video->ureq && video->ureq[i].req) - usb_ep_dequeue(video->ep, video->ureq[i].req); + INIT_LIST_HEAD(&video->ureqs); + INIT_LIST_HEAD(&video->req_free); + INIT_LIST_HEAD(&video->req_ready); + video->req_size = 0; + spin_unlock_irqrestore(&video->req_lock, flags); - uvc_video_free_requests(video); - uvcg_queue_enable(&video->queue, 0); - return 0; + /* + * 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; +} + +/* + * Enable the video stream. + */ +int uvcg_video_enable(struct uvc_video *video) +{ + int ret; + + if (video->ep == NULL) { + uvcg_info(&video->uvc->func, + "Video enable failed, device is uninitialized.\n"); + 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; @@ -525,7 +757,7 @@ int uvcg_video_enable(struct uvc_video *video, int enable) video->req_int_count = 0; - queue_work(video->async_wq, &video->pump); + uvc_video_ep_queue_initial_requests(video); return ret; } @@ -535,7 +767,10 @@ int uvcg_video_enable(struct uvc_video *video, int enable) */ 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); + INIT_LIST_HEAD(&video->req_ready); spin_lock_init(&video->req_lock); INIT_WORK(&video->pump, uvcg_video_pump); |