[media] dvb_demux: Transport stream continuity check fix

This patch avoids incrementing continuity counter
demux->cnt_storage[pid] for TS packets without payload in accordance
with ISO /IEC 13818-1.

[mchehab@redhat.com: unmangle whitespacing and fix CodingStyle.
 Also checked ISO/IEC spec: patch is according with it]
Reviewed-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: John Smith <johns90812@gmail.com>

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 13 insertions, 11 deletions

diff --git a/drivers/media/dvb-core/dvb_demux.c b/drivers/media/dvb-core/dvb_demux.c
index d319717eb535..71641b2dde6b 100644
--- a/drivers/media/dvb-core/dvb_demux.c
+++ b/drivers/media/dvb-core/dvb_demux.c
@@ -440,20 +440,22 @@ static void dvb_dmx_swfilter_packet(struct dvb_demux *demux, const u8 *buf)
                 if (!dvb_demux_feed_err_pkts)
                         return;
         } else /* if TEI bit is set, pid may be wrong- skip pkt counter */
-        if (demux->cnt_storage && dvb_demux_tscheck) {
-                /* check pkt counter */
-                if (pid < MAX_PID) {
-                        if ((buf[3] & 0xf) != demux->cnt_storage[pid])
-                                dprintk_tscheck("TS packet counter mismatch. "
-                                                "PID=0x%x expected 0x%x "
-                                                "got 0x%x\n",
+                if (demux->cnt_storage && dvb_demux_tscheck) {
+                        /* check pkt counter */
+                        if (pid < MAX_PID) {
+                                if (buf[3] & 0x10)
+                                        demux->cnt_storage[pid] =
+                                                (demux->cnt_storage[pid] + 1) & 0xf;
+
+                                if ((buf[3] & 0xf) != demux->cnt_storage[pid]) {
+                                        dprintk_tscheck("TS packet counter mismatch. PID=0x%x expected 0x%x got 0x%x\n",
                                                 pid, demux->cnt_storage[pid],
                                                 buf[3] & 0xf);
-
-                        demux->cnt_storage[pid] = ((buf[3] & 0xf) + 1)&0xf;
+                                        demux->cnt_storage[pid] = buf[3] & 0xf;
+                                }
+                        }
+                        /* end check */
                 }
-                /* end check */
-        }
 
         list_for_each_entry(feed, &demux->feed_list, list_head) {
                 if ((feed->pid != pid) && (feed->pid != 0x2000))