From: Ricardo Ribalda <ricardo.ribalda@gmail.com>
Date: Wed, 8 Jan 2014 08:01:33 +0000 (-0300)
Subject: upstream: [media] vb2: Check if there are buffers before streamon
X-Git-Tag: submit/tizen/20141121.110247~1496
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=02b986f5b1157bf06a5e7df033627f085be443bf;p=platform%2Fkernel%2Flinux-3.10.git

upstream: [media] vb2: Check if there are buffers before streamon

This patch adds a test preventing streamon() if there is no buffer
ready.

Without this patch, a user could call streamon() before
preparing any buffer. This leads to a situation where if he calls
close() before calling streamoff() the device is kept streaming.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
---

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 17c0b1c..06faea4 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1779,6 +1779,11 @@ static int vb2_internal_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
 		return 0;
 	}
 
+	if (!q->num_buffers) {
+		dprintk(1, "streamon: no buffers have been allocated\n");
+		return -EINVAL;
+	}
+
 	/*
 	 * If any buffers were queued before streamon,
 	 * we can now pass them to driver for processing.