From: Ricardo Ribalda <ricardo.ribalda@gmail.com>
Date: Wed, 8 Jan 2014 08:01:33 +0000 (-0300)
Subject: [media] vb2: Check if there are buffers before streamon
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=548df7831adc34eca3ccefa29f768cef84315d6e;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

[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 5a5fb7f09b7b..a127925c9d61 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1776,6 +1776,11 @@ 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.