media: aspeed: refine to avoid full jpeg update

The switch of jpeg 420/444 subsampling will update full jpeg header for
aspeed now.

Just update the 420/444 subsampling part of jpeg header is fine.
Signed-off-by: Jammy Huang <jammy_huang@aspeedtech.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/platform/aspeed-video.c

@@ -422,6 +422,21 @@ static void aspeed_video_init_jpeg_table(u32 *table, bool yuv420)
 	}
 }
 
+// just update jpeg dct table per 420/444
+static void aspeed_video_update_jpeg_table(u32 *table, bool yuv420)
+{
+	int i;
+	unsigned int base;
+
+	for (i = 0; i < ASPEED_VIDEO_JPEG_NUM_QUALITIES; i++) {
+		base = 256 * i;	/* AST HW requires this header spacing */
+		base += ASPEED_VIDEO_JPEG_HEADER_SIZE +
+			ASPEED_VIDEO_JPEG_DCT_SIZE;
+
+		table[base + 2] = (yuv420) ? 0x00220103 : 0x00110103;
+	}
+}
+
 static void aspeed_video_update(struct aspeed_video *video, u32 reg, u32 clear,
 				u32 bits)
 {
@@ -1289,7 +1304,7 @@ static void aspeed_video_update_jpeg_quality(struct aspeed_video *video)
 static void aspeed_video_update_subsampling(struct aspeed_video *video)
 {
 	if (video->jpeg.virt)
-		aspeed_video_init_jpeg_table(video->jpeg.virt, video->yuv420);
+		aspeed_video_update_jpeg_table(video->jpeg.virt, video->yuv420);
 
 	if (video->yuv420)
 		aspeed_video_update(video, VE_SEQ_CTRL, 0, VE_SEQ_CTRL_YUV420);