pespin has submitted this change. ( https://gerrit.osmocom.org/c/osmo-pcu/+/37678?usp=email )

Change subject: X2001 timeout: Update UL TBF's dl_ass_fsm state ......................................................................

X2001 timeout: Update UL TBF's dl_ass_fsm state

X2001 is the timer triggered after 2 seconds when a DL TBF is being assigned but the assignment never completes. A DL TBF can be PACCH-assigned using either: * Another DL TBF (usually the same object when upgrading to multislot) * A UL TBF.

The active UL/DL TBF doing the assignment of thew new DL TBF is the one holding the assignment state in its tbf.dl_ass_fsm. That FSM is checked by the scheduler to figure out whether a Pkt DL Ass needs to be transmitted.

if the new DL TBF being assigned was freed due to X2001, then the tbf.dl_ass_fsm of the TBF doing the assignment was not updating, meaning it was trying to send Pkt DL Ass by the scheduler, but it was erroring (properly) by a check in create_packet_dl_assign() validating a DL TBF (the oen being assigned) exists in the MS.

Change-Id: I42cc264b1b77bf8d91ec01a18d8985e182a20024 --- M src/tbf_dl_ass_fsm.c M src/tbf_dl_ass_fsm.h M src/tbf_dl_fsm.c 3 files changed, 50 insertions(+), 2 deletions(-)

Approvals: Jenkins Builder: Verified fixeria: Looks good to me, but someone else must approve pespin: Looks good to me, approved osmith: Looks good to me, but someone else must approve

diff --git a/src/tbf_dl_ass_fsm.c b/src/tbf_dl_ass_fsm.c index d811b71..1b6d97b 100644 --- a/src/tbf_dl_ass_fsm.c +++ b/src/tbf_dl_ass_fsm.c @@ -42,6 +42,7 @@ { TBF_DL_ASS_EV_CREATE_RLCMAC_MSG, "CREATE_RLCMAC_MSG" }, { TBF_DL_ASS_EV_RX_ASS_CTRL_ACK, "RX_ASS_CTRL_ACK" }, { TBF_DL_ASS_EV_ASS_POLL_TIMEOUT, "ASS_POLL_TIMEOUT" }, + { TBF_DL_ASS_EV_ABORT, "ABORT" }, { 0, NULL } };

@@ -163,6 +164,10 @@ return; tbf_dl_ass_fsm_state_chg(fi, TBF_DL_ASS_WAIT_ACK); break; + case TBF_DL_ASS_EV_ABORT: + /* Cancel pending schedule for Pkt Ul Ass: */ + tbf_dl_ass_fsm_state_chg(fi, TBF_DL_ASS_NONE); + break; default: OSMO_ASSERT(0); } @@ -183,6 +188,9 @@ /* Reschedule Pkt Dl Ass */ tbf_dl_ass_fsm_state_chg(fi, TBF_DL_ASS_SEND_ASS); break; + case TBF_DL_ASS_EV_ABORT: + tbf_dl_ass_fsm_state_chg(fi, TBF_DL_ASS_NONE); + break; default: OSMO_ASSERT(0); } @@ -208,7 +216,8 @@ .onenter = st_none_on_enter, }, [TBF_DL_ASS_SEND_ASS] = { - .in_event_mask = X(TBF_DL_ASS_EV_CREATE_RLCMAC_MSG), + .in_event_mask = X(TBF_DL_ASS_EV_CREATE_RLCMAC_MSG) | + X(TBF_DL_ASS_EV_ABORT), .out_state_mask = X(TBF_DL_ASS_WAIT_ACK) | X(TBF_DL_ASS_NONE), @@ -218,7 +227,8 @@ [TBF_DL_ASS_WAIT_ACK] = { .in_event_mask = X(TBF_DL_ASS_EV_RX_ASS_CTRL_ACK) | - X(TBF_DL_ASS_EV_ASS_POLL_TIMEOUT), + X(TBF_DL_ASS_EV_ASS_POLL_TIMEOUT) | + X(TBF_DL_ASS_EV_ABORT), .out_state_mask = X(TBF_DL_ASS_NONE) | X(TBF_DL_ASS_SEND_ASS), diff --git a/src/tbf_dl_ass_fsm.h b/src/tbf_dl_ass_fsm.h index cb7be8d..56c71c4 100644 --- a/src/tbf_dl_ass_fsm.h +++ b/src/tbf_dl_ass_fsm.h @@ -28,6 +28,7 @@ TBF_DL_ASS_EV_CREATE_RLCMAC_MSG, /* Scheduler wants to gen+Tx the Ass (rej): data=tbf_dl_ass_ev_create_rlcmac_msg_ctx */ TBF_DL_ASS_EV_RX_ASS_CTRL_ACK, /* Received CTRL ACK answering poll set on Pkt Dl Ass */ TBF_DL_ASS_EV_ASS_POLL_TIMEOUT, /* Pdch Ul Controller signals timeout for poll set on Pkt Dl Ass */ + TBF_DL_ASS_EV_ABORT, /* DL TBF being assigned was internally released */ };

enum tbf_dl_ass_fsm_states { diff --git a/src/tbf_dl_fsm.c b/src/tbf_dl_fsm.c index 917c4b1..400c242 100644 --- a/src/tbf_dl_fsm.c +++ b/src/tbf_dl_fsm.c @@ -411,6 +411,10 @@ static int tbf_dl_fsm_timer_cb(struct osmo_fsm_inst *fi) { struct tbf_dl_fsm_ctx *ctx = (struct tbf_dl_fsm_ctx *)fi->priv; + struct GprsMs *ms = NULL; + struct gprs_rlcmac_ul_tbf *ul_tbf = NULL; + struct gprs_rlcmac_tbf *tbf = NULL; + switch (fi->T) { case -2002: handle_timeout_X2002(fi); @@ -419,7 +423,14 @@ tbf_dl_fsm_state_chg(fi, TBF_ST_WAIT_REUSE_TFI); break; case -2001: + ms = tbf_ms(ctx->tbf); + ul_tbf = ms_ul_tbf(ms); + tbf = ul_tbf_as_tbf(ul_tbf); LOGPTBFDL(ctx->dl_tbf, LOGL_NOTICE, "releasing due to PACCH assignment timeout.\n"); + /* If a UL TBF is trying to assign us, notify it that we are + * dying so it avoids continuing the assignment. */ + if (ul_tbf && tbf_dl_ass_fi(tbf)->state != TBF_DL_ASS_NONE) + osmo_fsm_inst_dispatch(tbf_dl_ass_fi(tbf), TBF_DL_ASS_EV_ABORT, NULL); /* fall-through */ case 3193: case 3195: