laforge has submitted this change. (
https://gerrit.osmocom.org/c/osmo-bts/+/19029 )
Change subject: osmo-bts-trx/scheduler: refactor dummy burst scheduling
......................................................................
osmo-bts-trx/scheduler: refactor dummy burst scheduling
This change facilitates the upcoming freq. hopping implementation,
in particular scheduling of dummy bursts on C0 with hopping time-
slots. One problem is that we cannot know in advance, whether to
send a dummy burst on a given timeslot unless all transceivers are
processed. For example, trx#3 may want to send a normal burst on
ARFCN of trx#0 (C0), while we have already sent a dummy burst...
Another important aspect is that we shall not be sending dummy
bursts on transceivers other than C0. Scheduling dummy bursts
from _sched_dl_burst() in the context of a single hopping timeslot
of a single transceiver leaves trx_sched_fn() no way to know
whether it's a dummy burst or something else.
Let's solve both problems by moving dummy burst scheduling logic
from _sched_dl_burst() to trx_sched_fn(). Maintain C0 slot-mask
in the inner (per-trx) loop, so that we can fill missing bursts
with dummy bursts afterwards.
Change-Id: I8c3651c27d2991079e83b8abdb7e2c3f95b97a43
Related: SYS#4868, OS#4546
---
M include/osmo-bts/scheduler_backend.h
M src/common/scheduler.c
M src/osmo-bts-trx/scheduler_trx.c
3 files changed, 29 insertions(+), 17 deletions(-)
Approvals:
laforge: Looks good to me, approved
Hoernchen: Looks good to me, but someone else must approve
Jenkins Builder: Verified
diff --git a/include/osmo-bts/scheduler_backend.h
b/include/osmo-bts/scheduler_backend.h
index eb8039f..e3326f6 100644
--- a/include/osmo-bts/scheduler_backend.h
+++ b/include/osmo-bts/scheduler_backend.h
@@ -35,6 +35,7 @@
};
extern const struct trx_chan_desc trx_chan_desc[_TRX_CHAN_MAX];
+extern const ubit_t _sched_dummy_burst[];
extern const ubit_t _sched_tsc[8][26];
extern const ubit_t _sched_egprs_tsc[8][78];
extern const ubit_t _sched_sch_train[64];
diff --git a/src/common/scheduler.c b/src/common/scheduler.c
index 7375a1a..c5b3830 100644
--- a/src/common/scheduler.c
+++ b/src/common/scheduler.c
@@ -52,8 +52,9 @@
enum trx_chan_type chan);
static int rts_tchh_fn(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
enum trx_chan_type chan);
+
/*! \brief Dummy Burst (TS 05.02 Chapter 5.2.6) */
-static const ubit_t dummy_burst[GSM_BURST_LEN] = {
+const ubit_t _sched_dummy_burst[GSM_BURST_LEN] = {
0,0,0,
1,1,1,1,1,0,1,1,0,1,1,1,0,1,1,0,0,0,0,0,1,0,1,0,0,1,0,0,1,1,1,0,
0,0,0,0,1,0,0,1,0,0,0,1,0,0,0,0,0,0,0,1,1,1,1,1,0,0,0,1,1,1,0,0,
@@ -1189,7 +1190,7 @@
enum trx_chan_type chan;
if (!l1ts->mf_index)
- goto no_data;
+ return;
/* get frame from multiframe */
period = l1ts->mf_period;
@@ -1204,11 +1205,11 @@
/* check if channel is active */
if (!TRX_CHAN_IS_ACTIVE(l1cs, chan))
- goto no_data;
+ return;
/* get burst from function */
if (func(l1t, chan, bid, br) != 0)
- goto no_data;
+ return;
/* BS Power reduction (in dB) per logical channel */
if (l1cs->lchan != NULL)
@@ -1225,19 +1226,6 @@
br->burst[i + 88] ^= ks[i + 57];
}
}
-
-no_data:
- /* in case of C0, we need a dummy burst to maintain RF power */
- if (!br->burst_len && l1t->trx == l1t->trx->bts->c0) {
-#if 0
- if (chan != TRXC_IDLE) // hack
- LOGP(DL1C, LOGL_DEBUG, "No burst data for %s fn=%u
ts=%u "
- "burst=%d on C0, so filling with dummy burst\n",
- trx_chan_desc[chan].name, fn, tn, bid);
-#endif
- memcpy(br->burst, dummy_burst, ARRAY_SIZE(dummy_burst));
- br->burst_len = ARRAY_SIZE(dummy_burst);
- }
}
static int trx_sched_calc_frame_loss(struct l1sched_trx *l1t,
diff --git a/src/osmo-bts-trx/scheduler_trx.c b/src/osmo-bts-trx/scheduler_trx.c
index 85f0e92..e617031 100644
--- a/src/osmo-bts-trx/scheduler_trx.c
+++ b/src/osmo-bts-trx/scheduler_trx.c
@@ -60,6 +60,7 @@
{
struct trx_dl_burst_req br;
struct gsm_bts_trx *trx;
+ uint8_t c0_mask = 0x00;
uint32_t sched_fn;
uint8_t tn;
@@ -99,9 +100,31 @@
continue;
}
+ /* update dummy burst mask for C0 */
+ if (trx == bts->c0)
+ c0_mask |= (1 << tn);
+
trx_if_send_burst(l1h, &br);
}
}
+
+ /* send dummy bursts on inactive timeslots of C0 */
+ struct phy_instance *pinst = trx_phy_instance(bts->c0);
+ struct trx_l1h *l1h = pinst->u.osmotrx.hdl;
+ struct phy_link *plink = pinst->phy_link;
+
+ br = (struct trx_dl_burst_req) {
+ .fn = GSM_TDMA_FN_SUM(fn, plink->u.osmotrx.clock_advance),
+ .burst_len = GSM_BURST_LEN,
+ };
+
+ memcpy(br.burst, _sched_dummy_burst, GSM_BURST_LEN);
+
+ for (br.tn = 0; br.tn < TRX_NR_TS; br.tn++) {
+ if (c0_mask & (1 << br.tn))
+ continue;
+ trx_if_send_burst(l1h, &br);
+ }
}
/*! maximum number of 'missed' frame periods we can tolerate of OS doesn't
schedule us*/
--
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Gerrit-Project: osmo-bts
Gerrit-Branch: master
Gerrit-Change-Id: I8c3651c27d2991079e83b8abdb7e2c3f95b97a43
Gerrit-Change-Number: 19029
Gerrit-PatchSet: 4
Gerrit-Owner: fixeria <[email protected]>
Gerrit-Reviewer: Hoernchen <[email protected]>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: fixeria <[email protected]>
Gerrit-Reviewer: laforge <[email protected]>
Gerrit-CC: pespin <[email protected]>
Gerrit-MessageType: merged
