}
 }
 
+/* start of filler packet */
+static u8 fill_ts[] = { 0x47, 0x1f, 0xff, 0x10, TS_FILLER };
+
+/* #define DEBUG_CI_XFER */
+#ifdef DEBUG_CI_XFER
+static u32 ok;
+static u32 overflow;
+static u32 stripped;
+#endif
+
 void *tsin_exchange(void *priv, void *buf, u32 len, u32 clock, u32 flags)
 {
        struct ngene_channel *chan = priv;
 
        if (flags & DF_SWAP32)
                swap_buffer(buf, len);
+
        if (dev->ci.en && chan->number == 2) {
-               if (dvb_ringbuffer_free(&dev->tsin_rbuf) > len) {
-                       dvb_ringbuffer_write(&dev->tsin_rbuf, buf, len);
-                       wake_up_interruptible(&dev->tsin_rbuf.queue);
+               while (len >= 188) {
+                       if (memcmp(buf, fill_ts, sizeof fill_ts) != 0) {
+                               if (dvb_ringbuffer_free(&dev->tsin_rbuf) >= 188) {
+                                       dvb_ringbuffer_write(&dev->tsin_rbuf, buf, 188);
+                                       wake_up(&dev->tsin_rbuf.queue);
+#ifdef DEBUG_CI_XFER
+                                       ok++;
+#endif
+                               }
+#ifdef DEBUG_CI_XFER
+                               else
+                                       overflow++;
+#endif
+                       }
+#ifdef DEBUG_CI_XFER
+                       else
+                               stripped++;
+
+                       if (ok % 100 == 0 && overflow)
+                               printk(KERN_WARNING "%s: ok %u overflow %u dropped %u\n", __func__, ok, overflow, stripped);
+#endif
+                       buf += 188;
+                       len -= 188;
                }
-               return 0;
+               return NULL;
        }
+
        if (chan->users > 0)
                dvb_dmx_swfilter(&chan->demux, buf, len);
 
        return NULL;
 }
 
-u8 fill_ts[188] = { 0x47, 0x1f, 0xff, 0x10 };
-
 void *tsout_exchange(void *priv, void *buf, u32 len, u32 clock, u32 flags)
 {
        struct ngene_channel *chan = priv;