From 92918a53ee74bb326430aaa958caa0cf111b54b1 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Sun, 14 Jun 2009 06:21:35 -0300 Subject: [PATCH] V4L/DVB (12075): gspca_ov519: check ov518 packet numbers Check ov518 packet numbers to detect dropped packets. Signed-off-by: Hans de Goede Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/gspca/ov519.c | 29 +++++++++++++++++++++++------ 1 file 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 */ -- 2.43.2