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authorKieran Bingham <kieran.bingham@ideasonboard.com>2017-03-23 08:25:14 -0400
committerMauro Carvalho Chehab <mchehab+samsung@kernel.org>2018-12-05 03:10:06 -0500
commite829b262a6782ee36ee04e32a2fc7341385ac7fe (patch)
tree22240f51d2aafe89606bd23718732992a9eeda7f
parentc6d664fe8a7a47af1c63c037e20570d4abbda3c6 (diff)
downloadlinux-e829b262a6782ee36ee04e32a2fc7341385ac7fe.tar.bz2
media: uvcvideo: Protect queue internals with helper
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 <kieran.bingham@ideasonboard.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
-rw-r--r--drivers/media/usb/uvc/uvc_queue.c33
-rw-r--r--drivers/media/usb/uvc/uvc_video.c6
-rw-r--r--drivers/media/usb/uvc/uvcvideo.h1
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 35ba48769244..f6109a4dde5b 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -728,6 +728,7 @@ 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,