[PATCH] openbsc[master]: abis_om2000: for TS conf of dyn TS, always send TCH/F as cha...

[Neels Hofmeyr]

Hello Harald Welte, Jenkins Builder,

I'd like you to reexamine a change.  Please visit

    https://gerrit.osmocom.org/1218

to look at the new patch set (#2).

abis_om2000: for TS conf of dyn TS, always send TCH/F as chan comb

When OM2K sets up the timeslots with the BTS, the dynamic channel state
is not yet resolved to any particular pchan type. Instead of using the
dyn state, always advertise dynamic timeslots as TCH/F.

Initially, the Ericsson dynamic timeslots were handled as pchan type
TCH/F_PDCH. This a slight mistake, as this pchan type is intended for
the ip.access dynamic PDCH way of dynamic channels. In any case, in the
initial state of this pchan type, the timeslot was initialized as TCH/F
because the ts->flags do not reflect an active PDCH yet. In short, this
patch does not change the behavior of TCH/F_PDCH timeslots, only
clarifies it.

The proper pchan to use for Ericsson dynamic timeslots is
TCH/F_TCH/H_PDCH. These do not use ts->flags, but ts->dyn.* as state,
which first reflects pchan_want == pchan_is == GSM_PCHAN_NONE. Hence
the timeslot was initialized by OM2K as pchan type zero, which is
unknown / invalid. So, instead of using pchan_is, which is not yet
reflecting anything meaningful, always initialize as TCH/F chan comb,
as Ericsson hardware apparently expects it.

It would in fact make sense to disallow use of TCH/F_PDCH for OM2K,
but that should probably be a separate patch.

Change-Id: If0693f7c5c85977b0e4acbc701ee5d635434d0d1
---
M openbsc/src/libbsc/abis_om2000.c
1 file changed, 1 insertion(+), 5 deletions(-)


  git pull ssh://gerrit.osmocom.org:29418/openbsc refs/changes/18/1218/2

diff --git a/openbsc/src/libbsc/abis_om2000.c b/openbsc/src/libbsc/abis_om2000.c
index 1ab77b1..0890a15 100644
--- a/openbsc/src/libbsc/abis_om2000.c
+++ b/openbsc/src/libbsc/abis_om2000.c
@@ -1264,12 +1264,8 @@
 {
 	switch (ts->pchan) {
 	case GSM_PCHAN_TCH_F_PDCH:
-		if (ts->flags & TS_F_PDCH_ACTIVE)
-			return pchan2comb(GSM_PCHAN_PDCH);
-		else
-			return pchan2comb(GSM_PCHAN_TCH_F);
 	case GSM_PCHAN_TCH_F_TCH_H_PDCH:
-		return pchan2comb(ts->dyn.pchan_is);
+		return pchan2comb(GSM_PCHAN_TCH_F);
 	default:
 		return pchan2comb(ts->pchan);
 	}

-- 
To view, visit https://gerrit.osmocom.org/1218
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Gerrit-MessageType: newpatchset
Gerrit-Change-Id: If0693f7c5c85977b0e4acbc701ee5d635434d0d1
Gerrit-PatchSet: 2
Gerrit-Project: openbsc
Gerrit-Branch: master
Gerrit-Owner: dexter <pmaier at sysmocom.de>
Gerrit-Reviewer: Harald Welte <laforge at gnumonks.org>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: Neels Hofmeyr <nhofmeyr at sysmocom.de>