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authorHans de Goede <hdegoede@redhat.com>2009-06-14 06:21:35 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2009-06-23 03:11:40 -0300
commit92918a53ee74bb326430aaa958caa0cf111b54b1 (patch)
tree405033eaf382dd1e61f06c5e892802def6535c2c /drivers/media
parent124cc9c0c8acc77ac2f1114ee7eea961334020ba (diff)
V4L/DVB (12075): gspca_ov519: check ov518 packet numbers
Check ov518 packet numbers to detect dropped packets. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media')
-rw-r--r--drivers/media/video/gspca/ov519.c29
1 files changed, 23 insertions, 6 deletions
diff --git a/drivers/media/video/gspca/ov519.c b/drivers/media/video/gspca/ov519.c
index 55db32c95be..c2982137dc2 100644
--- a/drivers/media/video/gspca/ov519.c
+++ b/drivers/media/video/gspca/ov519.c
@@ -50,6 +50,8 @@ static int i2c_detect_tries = 10;
struct sd {
struct gspca_dev gspca_dev; /* !! must be the first item */
+ __u8 packet_nr;
+
char bridge;
#define BRIDGE_OV511 0
#define BRIDGE_OV511PLUS 1
@@ -2391,18 +2393,33 @@ static void ov518_pkt_scan(struct gspca_dev *gspca_dev,
__u8 *data, /* isoc packet */
int len) /* iso packet length */
{
- PDEBUG(D_STREAM, "ov518_pkt_scan: %d bytes", len);
-
- if (len & 7) {
- len--;
- PDEBUG(D_STREAM, "packet number: %d\n", (int)data[len]);
- }
+ struct sd *sd = (struct sd *) gspca_dev;
/* A false positive here is likely, until OVT gives me
* the definitive SOF/EOF format */
if ((!(data[0] | data[1] | data[2] | data[3] | data[5])) && data[6]) {
gspca_frame_add(gspca_dev, LAST_PACKET, frame, data, 0);
gspca_frame_add(gspca_dev, FIRST_PACKET, frame, data, 0);
+ sd->packet_nr = 0;
+ }
+
+ if (gspca_dev->last_packet_type == DISCARD_PACKET)
+ return;
+
+ /* Does this device use packet numbers ? */
+ if (len & 7) {
+ len--;
+ if (sd->packet_nr == data[len])
+ sd->packet_nr++;
+ /* The last few packets of the frame (which are all 0's
+ except that they may contain part of the footer), are
+ numbered 0 */
+ else if (sd->packet_nr == 0 || data[len]) {
+ PDEBUG(D_ERR, "Invalid packet nr: %d (expect: %d)",
+ (int)data[len], (int)sd->packet_nr);
+ gspca_dev->last_packet_type = DISCARD_PACKET;
+ return;
+ }
}
/* intermediate packet */