BTS_Tests/DTX: SACCH has nothing to do with fill frames

There is no such thing like a fill frame on SACCH:

  - on Downlink, it's always System Information messages;
  - on Uplink, it's always the Measurement Reports.

Yes, osmo-bts-trx does send dummy LAPDm func=UI frames on SACCH,
but this happens because the test suite never feds it with the
associated System Information messages (i.e. Type 5, 5ter, 6).

In the 'alt' statement, restrict matching of L1CTL DATA.ind, so
only DCCH/FACCH blocks are counted.  Ignore DL SACCH blocks.

This change reveals that TC_tch_sign_l2_fill_frame_dtxd actually
fails because no fill frames are received at all from the IUT.

Change-Id: I6c68dd0a7dfa18ae4573a037399b6650feb22f11
Related: OS#4801
1 file changed