Change in osmo-bsc[master]: lchan_fsm: Ignore other SAPIs of RLL_REL_IND for SAPI=0 is received

Attention is currently required from: laforge, pespin. fixeria has posted comments on this change. ( https://gerrit.osmocom.org/c/osmo-bsc/+/27818 ) Change subject: lchan_fsm: Ignore other SAPIs of RLL_REL_IND for SAPI=0 is received ...................................................................... Patch Set 1: (2 comments) File src/osmo-bsc/lchan_fsm.c: https://gerrit.osmocom.org/c/osmo-bsc/+/27818/comment/3decd69f_c0956b5d PS1, Line 1207: /* if SAPI=0 is gone, it makes no sense if other SAPIs are still around, Ack https://gerrit.osmocom.org/c/osmo-bsc/+/27818/comment/4a6db80f_e81d0fd8 PS1, Line 1210: * seem to send a RLL_REL_IND for SAPI=3 if there was already one for SAPI=0 */ Some of my notes made while trying to understand what's happening here. handle_rll_rel_ind_or_conf() is called on LCHAN_EV_RLL_REL_IND and LCHAN_EV_RLL_REL_CONF. These events are sent from abis_rsl_rx_rll() on receipt of RSL_MT_REL_IND and RSL_MT_REL_CONF, respectively. So we're dealing with the RSL specific coding of the link ID (which is different from DLCI). RSL Link Identifier is defined in 3GPP TS 3GPP TS 48.058, section 9.3.2, and coded as follows: .... .SSS - SAPI value used on the radio link; ...P P... - priority for SAPI0 messages; CC.. .... - control channel identification: 00.. .... - main signalling channel (FACCH or SDCCH), 01.. .... - SACCH, other values are reserved -- To view, visit https://gerrit.osmocom.org/c/osmo-bsc/+/27818 To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: osmo-bsc Gerrit-Branch: master Gerrit-Change-Id: Ia9caa5b0a5efdc459d94621367376927959a6e65 Gerrit-Change-Number: 27818 Gerrit-PatchSet: 1 Gerrit-Owner: laforge <laforge(a)osmocom.org> Gerrit-Reviewer: Jenkins Builder Gerrit-Reviewer: fixeria <vyanitskiy(a)sysmocom.de> Gerrit-CC: pespin <pespin(a)sysmocom.de> Gerrit-Attention: laforge <laforge(a)osmocom.org> Gerrit-Attention: pespin <pespin(a)sysmocom.de> Gerrit-Comment-Date: Wed, 20 Apr 2022 15:30:29 +0000 Gerrit-HasComments: Yes Gerrit-Has-Labels: No Comment-In-Reply-To: laforge <laforge(a)osmocom.org> Comment-In-Reply-To: pespin <pespin(a)sysmocom.de> Gerrit-MessageType: comment