From patchwork Tue Nov 6 21:27:14 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kieran Bingham X-Patchwork-Id: 52827 X-Patchwork-Delegate: laurent.pinchart@ideasonboard.com Received: from vger.kernel.org ([209.132.180.67]) by www.linuxtv.org with esmtp (Exim 4.84_2) (envelope-from ) id 1gK8so-0001ed-8f; Tue, 06 Nov 2018 21:27:34 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726558AbeKGGyn (ORCPT + 1 other); Wed, 7 Nov 2018 01:54:43 -0500 Received: from perceval.ideasonboard.com ([213.167.242.64]:55690 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726282AbeKGGyn (ORCPT ); Wed, 7 Nov 2018 01:54:43 -0500 Received: from localhost.localdomain (cpc89242-aztw30-2-0-cust488.18-1.cable.virginm.net [86.31.129.233]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 35DE458F; Tue, 6 Nov 2018 22:27:27 +0100 (CET) From: Kieran Bingham To: Laurent Pinchart , linux-media@vger.kernel.org Cc: Guennadi Liakhovetski , Olivier BRAUN , Troy Kisky , Randy Dunlap , Philipp Zabel , Ezequiel Garcia , Kieran Bingham Subject: [PATCH v5 3/9] media: uvcvideo: Protect queue internals with helper Date: Tue, 6 Nov 2018 21:27:14 +0000 Message-Id: X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org From: Kieran Bingham The URB completion operation obtains the current buffer by reading directly into the queue internal interface. Protect this queue abstraction by providing a helper uvc_queue_get_current_buffer() which can be used by both the decode task, and the uvc_queue_next_buffer() functions. Signed-off-by: Kieran Bingham Reviewed-by: Laurent Pinchart --- v2: - Fix coding style of conditional statements v3: - No change v4: - Rebase on top of linux-media/master (v4.16-rc4, metadata additions) drivers/media/usb/uvc/uvc_queue.c | 33 +++++++++++++++++++++++++++----- drivers/media/usb/uvc/uvc_video.c | 6 +----- drivers/media/usb/uvc/uvcvideo.h | 1 +- 3 files changed, 30 insertions(+), 10 deletions(-) diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c index 8964e16f2b22..74f9483911d0 100644 --- a/drivers/media/usb/uvc/uvc_queue.c +++ b/drivers/media/usb/uvc/uvc_queue.c @@ -430,6 +430,33 @@ void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect) spin_unlock_irqrestore(&queue->irqlock, flags); } +/* + * uvc_queue_get_current_buffer: Obtain the current working output buffer + * + * Buffers may span multiple packets, and even URBs, therefore the active buffer + * remains on the queue until the EOF marker. + */ +static struct uvc_buffer * +__uvc_queue_get_current_buffer(struct uvc_video_queue *queue) +{ + if (list_empty(&queue->irqqueue)) + return NULL; + + return list_first_entry(&queue->irqqueue, struct uvc_buffer, queue); +} + +struct uvc_buffer *uvc_queue_get_current_buffer(struct uvc_video_queue *queue) +{ + struct uvc_buffer *nextbuf; + unsigned long flags; + + spin_lock_irqsave(&queue->irqlock, flags); + nextbuf = __uvc_queue_get_current_buffer(queue); + spin_unlock_irqrestore(&queue->irqlock, flags); + + return nextbuf; +} + struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue, struct uvc_buffer *buf) { @@ -446,11 +473,7 @@ struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue, spin_lock_irqsave(&queue->irqlock, flags); list_del(&buf->queue); - if (!list_empty(&queue->irqqueue)) - nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer, - queue); - else - nextbuf = NULL; + nextbuf = __uvc_queue_get_current_buffer(queue); spin_unlock_irqrestore(&queue->irqlock, flags); buf->state = buf->error ? UVC_BUF_STATE_ERROR : UVC_BUF_STATE_DONE; diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c index 6d4384695964..7a7779e1b466 100644 --- a/drivers/media/usb/uvc/uvc_video.c +++ b/drivers/media/usb/uvc/uvc_video.c @@ -1484,11 +1484,7 @@ static void uvc_video_complete(struct urb *urb) return; } - spin_lock_irqsave(&queue->irqlock, flags); - if (!list_empty(&queue->irqqueue)) - buf = list_first_entry(&queue->irqqueue, struct uvc_buffer, - queue); - spin_unlock_irqrestore(&queue->irqlock, flags); + buf = uvc_queue_get_current_buffer(queue); if (vb2_qmeta) { spin_lock_irqsave(&qmeta->irqlock, flags); diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h index f7f8db6fc91a..bdb6d8daedab 100644 --- a/drivers/media/usb/uvc/uvcvideo.h +++ b/drivers/media/usb/uvc/uvcvideo.h @@ -725,6 +725,7 @@ int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type); void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect); struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue, struct uvc_buffer *buf); +struct uvc_buffer *uvc_queue_get_current_buffer(struct uvc_video_queue *queue); int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma); __poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,