confused by osmo-bts rsl.c:bts_supports_cm()

[Keith]

Hi All.

posting to the list here rather than going down the line of a ticket as
I'm using the nitb to configure my bts and so this may not be a bug, but
rather a missing back port to legacy. (which may not be appreciated
here, I'm aware!)

Anyway, this is the scenario:

I noticed a lack of audio with latest osmo-bts, and this log message:

<0000> rsl.c:1503 invalid mode/codec instructed by BSC, check BSC
configuration.

 I added some logging in osmo-bts to check what was being passed into
this line in rsl.c:

if (bts_supports_cm(lchan->ts->trx->bts, lchan->ts->pchan,
lchan->tch_mode) != 1)

and the values are 0 (zero), GSM_PCHAN_TCH_F_TCH_H_PDCH  and
GSM48_CMODE_SPEECH_AMR but bts_supports_cm() only checks against
GSM_PCHAN_TCH_F and GSM_PCHAN_TCH_H


Is it that osmo-bsc is sending the actual current channel mode now,
whereas the osmo-nitb is sending the configured mode, i.e.
TCH_F_TCH_H_PDCH ?? in which case, sorry to bother you, but I will ask:
should we try to keep basic functionality between BTS and nitb for a
little while longer :)


Or are we missing checks for all possible modes in rsl.c:bts_supports_cm()

Related commit: http://git.osmocom.org/osmo-bts/commit/src?id=a4bca1155


Thanks!!



k/