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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>
This commit is contained in:
Hans de Goede 2009-06-14 06:21:35 -03:00 committed by Mauro Carvalho Chehab
parent 124cc9c0c8
commit 92918a53ee
1 changed files with 23 additions and 6 deletions
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29
drivers/media/video/gspca/ov519.c
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@ -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 */