V4L/DVB: gspca - sonixj: Bad detection of the end of image

The 'end of image' block may be splitted between two ISOC packets.
This case was not tested, so, some images could be lost and concatenated
to previous one(s), raising 'frame overflow' errors.

Signed-off-by: Jean-François Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/gspca/sonixj.c b/drivers/media/video/gspca/sonixj.c
index 3c699ac5233f79941a1fced1005d3fceb3fdebef..72f830a6572cc26b1df4978cbcfd7d33a8c3533c 100644 (file)
--- a/drivers/media/video/gspca/sonixj.c
+++ b/drivers/media/video/gspca/sonixj.c
@@ -2820,38 +2820,52 @@ static void sd_pkt_scan(struct gspca_dev *gspca_dev,
        struct sd *sd = (struct sd *) gspca_dev;
        int sof, avg_lum;
 
-       sof = len - 64;
-       if (sof >= 0 && data[sof] == 0xff && data[sof + 1] == 0xd9) {
-
-               /* end of frame */
-               gspca_frame_add(gspca_dev, LAST_PACKET,
-                               data, sof + 2);
-               if (sd->ag_cnt < 0)
-                       return;
+       /* the image ends on a 64 bytes block starting with
+        *      ff d9 ff ff 00 c4 c4 96
+        * and followed by various information including luminosity */
+       /* this block may be splitted between two packets */
+       /* a new image always starts in a new packet */
+       switch (gspca_dev->last_packet_type) {
+       case DISCARD_PACKET:            /* restart image building */
+               sof = len - 64;
+               if (sof >= 0 && data[sof] == 0xff && data[sof + 1] == 0xd9)
+                       gspca_frame_add(gspca_dev, LAST_PACKET, NULL, 0);
+               return;
+       case LAST_PACKET:               /* put the JPEG 422 header */
+               gspca_frame_add(gspca_dev, FIRST_PACKET,
+                               sd->jpeg_hdr, JPEG_HDR_SZ);
+               break;
+       }
+       gspca_frame_add(gspca_dev, INTER_PACKET, data, len);
+
+       data = gspca_dev->image;
+       if (data == NULL)
+               return;
+       sof = gspca_dev->image_len - 64;
+       if (data[sof] != 0xff
+        || data[sof + 1] != 0xd9)
+               return;
+
+       /* end of image found - remove the trailing data */
+       gspca_dev->image_len = sof + 2;
+       gspca_frame_add(gspca_dev, LAST_PACKET, NULL, 0);
+       if (sd->ag_cnt < 0)
+               return;
 /* w1 w2 w3 */
 /* w4 w5 w6 */
 /* w7 w8 */
 /* w4 */
-               avg_lum = ((data[sof + 29] << 8) | data[sof + 30]) >> 6;
+       avg_lum = ((data[sof + 29] << 8) | data[sof + 30]) >> 6;
 /* w6 */
-               avg_lum += ((data[sof + 33] << 8) | data[sof + 34]) >> 6;
+       avg_lum += ((data[sof + 33] << 8) | data[sof + 34]) >> 6;
 /* w2 */
-               avg_lum += ((data[sof + 25] << 8) | data[sof + 26]) >> 6;
+       avg_lum += ((data[sof + 25] << 8) | data[sof + 26]) >> 6;
 /* w8 */
-               avg_lum += ((data[sof + 37] << 8) | data[sof + 38]) >> 6;
+       avg_lum += ((data[sof + 37] << 8) | data[sof + 38]) >> 6;
 /* w5 */
-               avg_lum += ((data[sof + 31] << 8) | data[sof + 32]) >> 4;
-               avg_lum >>= 4;
-               atomic_set(&sd->avg_lum, avg_lum);
-               return;
-       }
-       if (gspca_dev->last_packet_type == LAST_PACKET) {
-
-               /* put the JPEG 422 header */
-               gspca_frame_add(gspca_dev, FIRST_PACKET,
-                       sd->jpeg_hdr, JPEG_HDR_SZ);
-       }
-       gspca_frame_add(gspca_dev, INTER_PACKET, data, len);
+       avg_lum += ((data[sof + 31] << 8) | data[sof + 32]) >> 4;
+       avg_lum >>= 4;
+       atomic_set(&sd->avg_lum, avg_lum);
 }
 
 static int sd_setbrightness(struct gspca_dev *gspca_dev, __s32 val)