firedtv: use length_field() of PMT as length

Parsed and used the length_field() of the PMT message instead of using
the length field of the message struct, which does not seem to be filled
correctly by e.g. MythTV.

Signed-off-by: Henrik Kurelid <henrik@kurelid.se>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

1 files changed, 13 insertions, 7 deletions

diff --git a/drivers/media/dvb/firesat/firesat-ci.c b/drivers/media/dvb/firesat/firesat-ci.c
index 0deb47eefa10..783ed2000102 100644
--- a/drivers/media/dvb/firesat/firesat-ci.c
+++ b/drivers/media/dvb/firesat/firesat-ci.c
@@ -127,14 +127,20 @@ static int firesat_ca_pmt(struct firesat *firesat, void *arg)
 {
         struct ca_msg *msg = arg;
         int data_pos;
+        int data_length;
+        int i;
+
+        data_pos = 4;
+        if (msg->msg[3] & 0x80) {
+                data_length = 0;
+                for (i = 0; i < (msg->msg[3] & 0x7F); i++)
+                        data_length = (data_length << 8) + msg->msg[data_pos++];
+        } else {
+                data_length = msg->msg[3];
+        }
 
-        if (msg->msg[3] & 0x80)
-                data_pos = (msg->msg[4] && 0x7F) + 4;
-        else
-                data_pos = 4;
-
-        return avc_ca_pmt(firesat, &msg->msg[data_pos],
-                          msg->length - data_pos) ? -EFAULT : 0;
+        return avc_ca_pmt(firesat, &msg->msg[data_pos], data_length) ?
+               -EFAULT : 0;
 }
 
 static int firesat_ca_send_msg(struct firesat *firesat, void *arg)