| msc { |
| hscale=2; |
| bts [label="MS/BTS"], bsc[label="BSC"], bsc_ts[label="BSC timeslot FSM"], bsc_lchan[label="BSC lchan FSM"]; |
| |
| bsc box bsc [label="gsm_bts_alloc()"]; |
| bsc box bsc [label="bts->c0 = gsm_bts_trx_alloc()"]; |
| bsc -> bsc_ts; |
| bsc_ts box bsc_ts [label="trx->ts[*].fi = osmo_fsm_inst_alloc(timeslot_fsm)"]; |
| bsc_ts abox bsc_ts [label="TS_ST_NOT_INITIALIZED"]; |
| bsc -> bsc_lchan; |
| bsc_lchan box bsc_lchan [label="ts->lchan[*].ts = ts;\nts->lchan[*].nr = i;"]; |
| bsc_lchan box bsc_lchan [label="ts->lchan[*].fi = NULL"]; |
| bsc_ts note bsc_lchan [label="lchan_select() will only pick lchans from initialized timeslots of |
| the right pchan kind. lchan_select() shall OSMO_ASSERT(lchan->fi)."]; |
| ...; |
| ...; |
| |
| bts rbox bsc_lchan [label="reading config file"]; |
| ...; |
| bsc box bsc [label="timeslot N"]; |
| bsc box bsc [label="phys_chan_config X"]; |
| bsc_ts box bsc_ts [label="ts->pchan_from_config = X"]; |
| bsc_ts note bsc_ts [label="still TS_ST_NOT_INITIALIZED"]; |
| ...; |
| bsc box bsc [label="trx 1..*"]; |
| bsc box bsc [label="bts->trx_list add gsm_bts_trx_alloc()"]; |
| bsc_ts rbox bsc_lchan [label="same as for c0 above"]; |
| ...; |
| ...; |
| bts rbox bsc_lchan [label="Starting Operation"]; |
| bts => bsc_ts [label="OML Channel OPSTART ACK"]; |
| bsc_ts box bsc_ts [label="ts_on_oml_opstart()"]; |
| bsc_ts box bsc_ts [label="ts->pchan_on_init = pchan_from_config"]; |
| --- [label="IF dedicated TS"]; |
| bsc_ts box bsc_ts [label="ts->pchan = ts->pchan_on_init"]; |
| --- [label="ELSE: dyn TS"]; |
| bsc_ts box bsc_ts [label="ts->pchan = NONE"]; |
| --- [label="END: dyn TS"]; |
| bsc_ts note bsc_lchan [label="Normally, the lchan FSM never terminates. Logic dictates that |
| the lchan is a child of the timeslot FSM, but it's not actually of functional importance |
| beyond basic sanity. Parent term event: TS_EV_LCHAN_UNUSED"]; |
| bsc_ts box bsc_ts [label="Determine N = maximum number of lchans applicable to pchan_on_init"]; |
| bsc_ts -> bsc_lchan; |
| bsc_lchan box bsc_lchan [label="ts->lchan[all N].type = osmo_fsm_inst_alloc(lchan_fsm)"]; |
| bsc_lchan abox bsc_lchan [label="LCHAN_ST_UNUSED\n(initial state)"]; |
| bsc_ts -> bsc_ts [label="ts_check_init()"]; |
| ...; |
| bsc -> bsc_ts [label="RSL bootstrapped"]; |
| bsc_ts -> bsc_ts [label="ts_check_init()"]; |
| ...; |
| bsc_ts box bsc_ts [label="ts_check_init()"]; |
| --- [label="as soon as both OML and RSL are ready:"]; |
| bsc_ts box bsc_ts [label="ts_on_init()"]; |
| bsc_ts abox bsc_ts [label="TS_ST_UNUSED"]; |
| --- [label="dyn TS"]; |
| bsc_ts box bsc_ts [label="onenter of TS_ST_UNUSED:"]; |
| bsc_ts abox bsc_ts [label="TS_ST_WAIT_PDCH_ACT"]; |
| ...; |
| bsc_ts abox bsc_ts [label="PDCH"]; |
| --- [label="END: dyn TS"]; |
| --- [label="END: OML and RSL ready"]; |
| ...; |
| bsc box bsc [label="lchan_select() picks an unused lchan"]; |
| bsc -> bsc_lchan [label="lchan_allocate()"]; |
| bsc_lchan -> bsc_ts [label="TS_EV_LCHAN_REQUESTED"]; |
| |
| --- [label="dyn TS"]; |
| bsc_ts note bsc_ts [label="possibly switch from PDCH...\n(see timeslot FSM)"]; |
| bsc_ts box bsc_ts [label="ts->pchan =\n requested GSM_PCHAN_XXX type"]; |
| ---; |
| |
| bsc_ts -> bsc_lchan [label="LCHAN_EV_TS_READY"]; |
| bsc_lchan note bsc_lchan [label="RSL Chan Alloc and so fort..."]; |
| bsc_lchan abox bsc_lchan [label="LCHAN_ST_ACTIVE"]; |
| ...; |
| bsc -> bsc_lchan [label="LCHAN_EV_RELEASE"]; |
| bsc_lchan note bsc_lchan [label="...RSL RF Chan Release..."]; |
| bsc_lchan abox bsc_lchan [label="LCHAN_ST_UNUSED"]; |
| bsc_ts <- bsc_lchan [label="TS_EV_LCHAN_UNUSED"]; |
| bsc_ts abox bsc_ts [label="TS_ST_UNUSED"]; |
| --- [label="dyn TS"]; |
| bsc_ts note bsc_ts [label="possibly switch to PDCH"]; |
| ---; |
| ...; |
| ...; |
| bts rbox bsc_lchan [label="BTS RSL is dropped"]; |
| bsc box bsc [label="ipaccess_drop_rsl()"]; |
| bsc -> bsc_ts [label="ts[*]:"]; |
| bsc_ts abox bsc_ts [label="TS_ST_NOT_INITIALIZED"]; |
| bsc_ts note bsc_lchan [label="If it's just the RSL being dropped, transition lchan FSMs to |
| LCHAN_ST_UNUSED, but keep them allocated. Unless OML is re-established, any vty pchan |
| modifications must not take effect."]; |
| bsc_ts -> bsc_lchan [label="lchan[*]:"]; |
| bsc_lchan abox bsc_lchan [label="LCHAN_ST_UNUSED"]; |
| bsc_ts <- bsc_lchan [label="TS_EV_LCHAN_UNUSED (ignored)"]; |
| ...; |
| --- [label="when RSL comes back later:"]; |
| bsc -> bsc_ts [label="RSL bootstrapped"]; |
| bsc_ts box bsc_ts [label="ts_check_init()"]; |
| bsc_ts rbox bsc_ts [label="see ts_check_init() above"]; |
| ...; |
| ...; |
| bts rbox bsc_lchan [label="BTS OML is dropped"]; |
| bsc note bsc [label="As part of OML drop, RSL is also dropped:"]; |
| bsc box bsc [label="ipaccess_drop_rsl()"]; |
| bsc -> bsc_ts [label="ts[*]:"]; |
| bsc_ts abox bsc_ts [label="TS_ST_NOT_INITIALIZED"]; |
| bsc rbox bsc [label="see 'BTS RSL is dropped' above"]; |
| bsc -> bsc_ts [label="ts[*]:"]; |
| bsc_ts -> bsc_lchan [label="lchan[*]:"]; |
| bsc_lchan box bsc_lchan [label="osmo_fsm_inst_term()"]; |
| bsc_ts <- bsc_lchan [label="TS_EV_LCHAN_UNUSED (ignored)"]; |
| bsc_lchan box bsc_lchan [label="lchan->fi = NULL"]; |
| bsc rbox bsc [label="Continue at 'Starting Operation'"]; |
| |
| } |