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tbf: Don't change type from CCCH to PACCH without ack 

Currently the CCCH flag is cleared and the PACCH flag is set when a
multislot upgrade is scheduled for a downlink TBF, even if the MS has
never confirmed in any way that the PACCH really exists. This can
happen if the MS did not receive the DL IMM.ASS. Since the CCCH flags
gets cleared in that case, the IMM.ASSS is never retried and all
subsequent PACKET DOWNLINK ASSIGNMENTS will fail.

This commit delays the update of these flags until the MS has
responded with a corresponding CONTROL ACK.

Sponsored-by: On-Waves ehf
This commit is contained in:
Jacob Erlbeck 2016-01-29 18:51:04 +01:00
parent 6b356a58d1
commit 9876a3ba5d
2 changed files with 11 additions and 2 deletions
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12
src/bts.cpp
View File

@ -569,7 +569,8 @@ void BTS::trigger_dl_ass(
/* change state */
dl_tbf->set_state(GPRS_RLCMAC_ASSIGN);
dl_tbf->state_flags |= (1 << GPRS_RLCMAC_FLAG_PACCH);
if (!(dl_tbf->state_flags & (1 << GPRS_RLCMAC_FLAG_CCCH)))
dl_tbf->state_flags |= (1 << GPRS_RLCMAC_FLAG_PACCH);
/* start timer */
tbf_timer_start(dl_tbf, 0, Tassign_pacch);
} else {
@ -799,6 +800,15 @@ void gprs_rlcmac_pdch::rcv_control_ack(Packet_Control_Acknowledgement_t *packet,
if (tbf->state_is(GPRS_RLCMAC_WAIT_RELEASE))
tbf_free(tbf);
if ((new_tbf->state_flags & (1 << GPRS_RLCMAC_FLAG_CCCH))) {
/* We now know that the PACCH really existed */
LOGP(DRLCMAC, LOGL_INFO,
"The TBF has been confirmed on the PACCH, "
"changed type from CCCH to PACCH for %s\n",
tbf_name(new_tbf));
new_tbf->state_flags &= ~(1 << GPRS_RLCMAC_FLAG_CCCH);
new_tbf->state_flags |= (1 << GPRS_RLCMAC_FLAG_PACCH);
}
new_tbf->set_state(GPRS_RLCMAC_FLOW);
/* stop pending assignment timer */
new_tbf->stop_timer();

1
src/tbf.cpp
View File

@ -851,7 +851,6 @@ void gprs_rlcmac_tbf::handle_timeout()
/* keep to flags */
dl_tbf->state_flags &= GPRS_RLCMAC_FLAG_TO_MASK;
dl_tbf->state_flags &= ~(1 << GPRS_RLCMAC_FLAG_CCCH);
dl_tbf->update();