Hi,

I've added a print after the call to the uplink assignment function:

if (usf < 0) {

LOGP(DRLCMAC, LOGL_NOTICE, "- Failed "

"allocating TS=%d, no USF available\n", ts);

return -EBUSY;

}

LOGP(DRLCMAC, LOGL_DEBUG, "- Assign uplink "

"TS=%d USF=%d\n", ts, usf);

assign_uplink_tbf_usf(bts, pdch, ts, tbf, usf);

LOGP(DRLCMAC, LOGL_NOTICE, "USF allocated %d ts %d\n", tbf->dir.ul.usf[ts], ts);

Two MSs are getting different USFs now:

<0001> pcu_l1_if.cpp:290 RACH request received: sapi=1 qta=1, ra=123, fn=1109521

<0002> gprs_rlcmac.cpp:454 USF allocated 0 ts 7

<0002> gprs_rlcmac_data.cpp:1906 Got IMM.ASS confirm, but rest octets do not start with bit sequence 'HH01' (Packet Downlink Assignment)

<0001> pcu_l1_if.cpp:290 RACH request received: sapi=1 qta=1, ra=121, fn=1109533

<0002> gprs_rlcmac.cpp:454 USF allocated 1 ts 7

<0002> gprs_rlcmac_data.cpp:1906 Got IMM.ASS confirm, but rest octets do not start with bit sequence 'HH01' (Packet Downlink Assignment)

<0008> gprs_rlcmac.cpp:1799 LLC [PCU -> SGSN] TFI: 0 TLLI: 0xc0a3df97 len=79

<0008> gprs_bssgp_pcu.cpp:155 LLC [SGSN -> PCU] = TLLI: 0xc0a3df97 IMSI: 334020481442858 len: 191

<0007> gprs_rlcmac_meas.cpp:102 UL RSSI of TLLI=0xc0a3df97: 0 dBm

<0008> gprs_rlcmac.cpp:1799 LLC [PCU -> SGSN] TFI: 1 TLLI: 0xf844d86d len=8

<0007> gprs_rlcmac_meas.cpp:102 UL RSSI of TLLI=0xf844d86d: 0 dBm

<0002> gprs_rlcmac_data.cpp:1549 Polling sheduled in this TS 7, FN 1109736

And it works. Both of them succeeded to open the internet page..

Without deep investigation alloc_b works as well (after patch applying).

Regards,

Vladimir.

On Wed, Sep 25, 2013 at 1:11 PM, Holger Hans Peter Freyther <hfreyther@sysmocom.de> wrote:

On Tue, Sep 24, 2013 at 01:26:17PM +0300, Vladimir Rolbin wrote:
> Hi all,
>
> It looks like usf found (allocated) is never used. I guess something
> like tbf->dir.ul.usf[ts] = usf is missed.

Hi!

can you indicate on how to re-produce the problem and how much time
you have spent in analyzing this problem? I have indicated the lack
of test cases in the past.

I moved the "assignment" (having to pass trx, bts, pdch, ts just
indicates the lack of structure in this code...) into a new method.
It kills code duplication and could fix the issue. I have only compile
tested it. Could you give it a try?

holger

diff --git a/src/gprs_rlcmac.cpp b/src/gprs_rlcmac.cpp
index 1d1a8c6..695bf47 100644
--- a/src/gprs_rlcmac.cpp
+++ b/src/gprs_rlcmac.cpp
@@ -402,6 +402,17 @@ next_diagram:
return tbf;
}

+static void assign_uplink_tbf_usf(struct gprs_rlcmac_bts *bts,
+ struct gprs_rlcmac_pdch *pdch,
+ int ts,
+ struct gprs_rlcmac_tbf *tbf, int8_t usf)
+{
+ bts->trx[tbf->trx].ul_tbf[tbf->tfi] = tbf;
+ pdch->ul_tbf[tbf->tfi] = tbf;
+ tbf->pdch[ts] = pdch;
+ tbf->dir.ul.usf[ts] = usf;
+}
+
/* Slot Allocation: Algorithm A
*
* Assign single slot for uplink and downlink
@@ -433,17 +444,14 @@ int alloc_algorithm_a(struct gprs_rlcmac_bts *bts,
if (tbf->direction == GPRS_RLCMAC_UL_TBF) {
/* if USF available */
usf = find_free_usf(pdch, ts);
- if (usf >= 0) {
- LOGP(DRLCMAC, LOGL_DEBUG, "- Assign uplink "
- "TS=%d USF=%d\n", ts, usf);
- bts->trx[tbf->trx].ul_tbf[tbf->tfi] = tbf;
- pdch->ul_tbf[tbf->tfi] = tbf;
- tbf->pdch[ts] = pdch;
- } else {
+ if (usf < 0) {
LOGP(DRLCMAC, LOGL_NOTICE, "- Failed "
"allocating TS=%d, no USF available\n", ts);
return -EBUSY;
}
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Assign uplink "
+ "TS=%d USF=%d\n", ts, usf);
+ assign_uplink_tbf_usf(bts, pdch, ts, tbf, usf);
} else {
LOGP(DRLCMAC, LOGL_DEBUG, "- Assign downlink TS=%d\n", ts);
bts->trx[tbf->trx].dl_tbf[tbf->tfi] = tbf;
@@ -859,10 +867,7 @@ int alloc_algorithm_b(struct gprs_rlcmac_bts *bts,
LOGP(DRLCMAC, LOGL_DEBUG, "- Assigning UL TS "
"%d\n", ts);
pdch = &bts->trx[tbf->trx].pdch[ts];
- bts->trx[tbf->trx].ul_tbf[tbf->tfi] = tbf;
- pdch->ul_tbf[tbf->tfi] = tbf;
- tbf->pdch[ts] = pdch;
- tbf->dir.ul.usf[ts] = usf[ts];
+ assign_uplink_tbf_usf(bts, pdch, ts, tbf, usf[ts]);
slotcount++;
if (slotcount == 1)
tbf->first_ts = ts;

--
- Holger Freyther <hfreyther@sysmocom.de> http://www.sysmocom.de/
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