[COMMON] media: smfc: invalid the cache lines as little as possible

The amount of data to invalidate CPU cache lines of the destination
buffer of the JPEG compression is much smaller than the length of
the destination buffer because the userspace tends to qbuf the buffer
that is large enough to store the uncompressed image.
Therefore, the data amount of invaidation on the destination buffer
needs to be less than the buffer size for less delay in cache
invalidation and vb2_ion_buf_finish_exact() is for that purpose.

Change-Id: Ifc069a3e940f4e470a2947dc249704340cbe5abb
Signed-off-by: Cho KyongHo <pullip.cho@samsung.com>

diff --git a/drivers/media/platform/exynos/smfc/smfc.c b/drivers/media/platform/exynos/smfc/smfc.c
index 8f2ed0be3f5f360093eb4419b538ab33c8ae7da1..a319336534cfc66578c20f8234f359ba19caa3df 100644 (file)
--- a/drivers/media/platform/exynos/smfc/smfc.c
+++ b/drivers/media/platform/exynos/smfc/smfc.c
@@ -290,6 +290,11 @@ static int smfc_vb2_buf_prepare(struct vb2_buffer *vb)
 
 static void smfc_vb2_buf_finish(struct vb2_buffer *vb)
 {
+       /*
+        * FIXME: develop how to maintain a part of buffer
+       if (!(vb->v4l2_buf.flags & V4L2_BUF_FLAG_NO_CACHE_INVALIDATE))
+               vb2_ion_buf_finish_exact(vb);
+        */
 }
 
 static void smfc_vb2_buf_cleanup(struct vb2_buffer *vb)