media: hantro: Reduce H264 extra space for motion vectors

A decoded 8-bit 4:2:0 frame need memory for up to 448 bytes per
macroblock with additional 32 bytes on multi-core variants.

Memory layout is as follow:

+---------------------------+
| Y-plane   256 bytes x MBs |
+---------------------------+
| UV-plane  128 bytes x MBs |
+---------------------------+
| MV buffer  64 bytes x MBs |
+---------------------------+
| MC sync          32 bytes |
+---------------------------+

Reduce the extra space allocated now that motion vector buffer offset no
longer is based on the extra space.

Only allocate extra space for 64 bytes x MBs of motion vector buffer
and 32 bytes for multi-core sync.

Fixes: a9471e25629b ("media: hantro: Add core bits to support H264 decoding")
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

diff --git a/drivers/staging/media/hantro/hantro_v4l2.c b/drivers/staging/media/hantro/hantro_v4l2.c
index fcf95c1d39ca6a63c78a4387077ce67565c75b8b..1dae76f20034d1316e539f6687755316c1690791 100644 (file)
--- a/drivers/staging/media/hantro/hantro_v4l2.c
+++ b/drivers/staging/media/hantro/hantro_v4l2.c
@@ -240,14 +240,30 @@ static int vidioc_try_fmt(struct file *file, void *priv, struct v4l2_format *f,
                v4l2_fill_pixfmt_mp(pix_mp, fmt->fourcc, pix_mp->width,
                                    pix_mp->height);
                /*
+                * A decoded 8-bit 4:2:0 NV12 frame may need memory for up to
+                * 448 bytes per macroblock with additional 32 bytes on
+                * multi-core variants.
+                *
                 * The H264 decoder needs extra space on the output buffers
                 * to store motion vectors. This is needed for reference
                 * frames.
+                *
+                * Memory layout is as follow:
+                *
+                * +---------------------------+
+                * | Y-plane   256 bytes x MBs |
+                * +---------------------------+
+                * | UV-plane  128 bytes x MBs |
+                * +---------------------------+
+                * | MV buffer  64 bytes x MBs |
+                * +---------------------------+
+                * | MC sync          32 bytes |
+                * +---------------------------+
                 */
                if (ctx->vpu_src_fmt->fourcc == V4L2_PIX_FMT_H264_SLICE)
                        pix_mp->plane_fmt[0].sizeimage +=
-                               128 * DIV_ROUND_UP(pix_mp->width, 16) *
-                                     DIV_ROUND_UP(pix_mp->height, 16);
+                               64 * MB_WIDTH(pix_mp->width) *
+                                    MB_WIDTH(pix_mp->height) + 32;
        } else if (!pix_mp->plane_fmt[0].sizeimage) {
                /*
                 * For coded formats the application can specify