From daaffd5f71cac170c2eabc4f36c7013ff70968e4 Mon Sep 17 00:00:00 2001
From: Brandon Philips <brandon@ifup.org>
Date: Wed, 2 Apr 2008 18:10:59 -0300
Subject: [PATCH] --- yaml --- r: 92591 b: refs/heads/master c:
 ce54093cefd64c1a2cb6b8c5ed1d68d2bd7a34ab h: refs/heads/master i:   92589:
 98b28d4f993eeb7c55467030576c264bad86e99e   92587:
 4a009aa9608dd745921ebba324a4fd026b66c13d   92583:
 1b4cd23d5807e3295e7c60bf2ccf1334cb42e6dc   92575:
 e4dafbb7f7d1a163c0a91c023e356cd8e5bd759d v: v3

---
 [refs]                                      |  2 +-
 trunk/drivers/media/video/videobuf-dma-sg.c | 16 +++++++++++++++-
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 12ea06546a29..2e1771dbff2f 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 137d1cb19d9da163ce6cb57a6fa1e6a3468af6a4
+refs/heads/master: ce54093cefd64c1a2cb6b8c5ed1d68d2bd7a34ab
diff --git a/trunk/drivers/media/video/videobuf-dma-sg.c b/trunk/drivers/media/video/videobuf-dma-sg.c
index 717783fa8b3e..e6ce99ff7fd1 100644
--- a/trunk/drivers/media/video/videobuf-dma-sg.c
+++ b/trunk/drivers/media/video/videobuf-dma-sg.c
@@ -546,6 +546,14 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
 		goto done;
 	}
 
+	/* This function maintains backwards compatibility with V4L1 and will
+	 * map more than one buffer if the vma length is equal to the combined
+	 * size of multiple buffers than it will map them together.  See
+	 * VIDIOCGMBUF in the v4l spec
+	 *
+	 * TODO: Allow drivers to specify if they support this mode
+	 */
+
 	/* look for first buffer to map */
 	for (first = 0; first < VIDEO_MAX_FRAME; first++) {
 		if (NULL == q->bufs[first])
@@ -590,10 +598,16 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
 	map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
 	if (NULL == map)
 		goto done;
-	for (size = 0, i = first; i <= last; size += q->bufs[i++]->bsize) {
+
+	size = 0;
+	for (i = first; i <= last; i++) {
+		if (NULL == q->bufs[i])
+			continue;
 		q->bufs[i]->map   = map;
 		q->bufs[i]->baddr = vma->vm_start + size;
+		size += q->bufs[i]->bsize;
 	}
+
 	map->count    = 1;
 	map->start    = vma->vm_start;
 	map->end      = vma->vm_end;