V4L/DVB (6714): ivtv: yuv frame parameter fix

Inadvertently missed a line when converting code to new hardware buffering
method. In some circumstances, this would lead to a frame being displayed
using parameters belonging to another frame.

Signed-off-by: Ian Armstrong <ian@iarmst.demon.co.uk>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/media/video/ivtv/ivtv-irq.c b/drivers/media/video/ivtv/ivtv-irq.c
index fc8eac09584c..8c00d8f6d4d9 100644
--- a/drivers/media/video/ivtv/ivtv-irq.c
+++ b/drivers/media/video/ivtv/ivtv-irq.c
@@ -797,7 +797,7 @@ static void ivtv_irq_vsync(struct ivtv *itv)
                 /* Check if we need to update the yuv registers */
                 if ((yi->yuv_forced_update || yi->new_frame_info[last_dma_frame].update) && last_dma_frame != -1) {
                         if (!yi->new_frame_info[last_dma_frame].update)
-                                last_dma_frame = (last_dma_frame - 1) & 3;
+                                last_dma_frame = (u8)(last_dma_frame - 1) % IVTV_YUV_BUFFERS;
 
                         if (yi->new_frame_info[last_dma_frame].src_w) {
                                 yi->update_frame = last_dma_frame;