diff --git a/src/nacc_fsm.c b/src/nacc_fsm.c
index 21af485..cc75238 100644
--- a/src/nacc_fsm.c
+++ b/src/nacc_fsm.c
@@ -168,7 +168,7 @@
 	struct GprsMs *ms = tbf_ms(tbf);
 	unsigned int rrbp;
 
-	rc = tbf_check_polling(tbf, data->fn, data->pdch->ts_no, new_poll_fn, &rrbp);
+	rc = tbf_check_polling(tbf, data->pdch, data->fn, new_poll_fn, &rrbp);
 	if (rc < 0) {
 		LOGP(DTBF, LOGL_ERROR, "Failed registering poll for Pkt Cell Chg Continue (%d)\n", rc);
 		return NULL;
diff --git a/src/tbf.cpp b/src/tbf.cpp
index 0af738d..70e3e6c 100644
--- a/src/tbf.cpp
+++ b/src/tbf.cpp
@@ -458,27 +458,6 @@
 	osmo_timer_schedule(&Tarr[t], sec, microsec);
 }
 
-int gprs_rlcmac_tbf::check_polling(uint32_t fn, uint8_t ts,
-	uint32_t *poll_fn_, unsigned int *rrbp_) const
-{
-	int rc;
-	if (!tbf_is_control_ts(this, &this->trx->pdch[ts])) {
-		LOGPTBF(this, LOGL_DEBUG, "Polling cannot be "
-			"scheduled in this TS %d (control TS %s)\n",
-			ts, pdch_name(control_ts));
-		return -EINVAL;
-	}
-
-	if ((rc = pdch_ulc_get_next_free_rrbp_fn(trx->pdch[ts].ulc, fn, poll_fn_, rrbp_)) < 0) {
-		LOGPTBF(this, LOGL_NOTICE,
-			"(bts=%u,trx=%u,ts=%u) FN=%u No suitable free RRBP offset found!\n",
-			trx->bts->nr, trx->trx_no, ts, fn);
-		return rc;
-	}
-
-	return 0;
-}
-
 void gprs_rlcmac_tbf::set_polling(uint32_t new_poll_fn, uint8_t ts, enum pdch_ulc_tbf_poll_reason reason)
 {
 	/* schedule polling */
@@ -839,9 +818,29 @@
 	return tbf->is_egprs_enabled();
 }
 
-int tbf_check_polling(const struct gprs_rlcmac_tbf *tbf, uint32_t fn, uint8_t ts, uint32_t *poll_fn, unsigned int *rrbp)
+int tbf_check_polling(const struct gprs_rlcmac_tbf *tbf, const struct gprs_rlcmac_pdch *pdch,
+		      uint32_t fn, uint32_t *poll_fn, unsigned int *rrbp)
 {
-	return tbf->check_polling(fn, ts, poll_fn, rrbp);
+	int rc;
+	OSMO_ASSERT(pdch);
+
+	if (!tbf_is_control_ts(tbf, pdch)) {
+		char buf[128];
+		LOGPTBF(tbf, LOGL_DEBUG, "Polling cannot be "
+			"scheduled in this TS %s (control TS %s)\n",
+			pdch_name(pdch),
+			tbf->control_ts ? pdch_name_buf(tbf->control_ts, buf, sizeof(buf)) : "none");
+		return -EINVAL;
+	}
+
+	if ((rc = pdch_ulc_get_next_free_rrbp_fn(pdch->ulc, fn, poll_fn, rrbp)) < 0) {
+		LOGPTBF(tbf, LOGL_NOTICE,
+			"FN=%u No suitable free RRBP offset found on %s!\n",
+			fn, pdch_name(pdch));
+		return rc;
+	}
+
+	return 0;
 }
 
 void tbf_set_polling(struct gprs_rlcmac_tbf *tbf, uint32_t new_poll_fn, uint8_t ts, enum pdch_ulc_tbf_poll_reason t)
diff --git a/src/tbf.h b/src/tbf.h
index a02b8e2..1d5d4f1 100644
--- a/src/tbf.h
+++ b/src/tbf.h
@@ -139,7 +139,7 @@
 uint8_t tbf_tfi(const struct gprs_rlcmac_tbf *tbf);
 bool tbf_is_egprs_enabled(const struct gprs_rlcmac_tbf *tbf);
 void tbf_assign_control_ts(struct gprs_rlcmac_tbf *tbf);
-int tbf_check_polling(const struct gprs_rlcmac_tbf *tbf, uint32_t fn, uint8_t ts, uint32_t *poll_fn, unsigned int *rrbp);
+int tbf_check_polling(const struct gprs_rlcmac_tbf *tbf, const struct gprs_rlcmac_pdch *pdch, uint32_t fn, uint32_t *poll_fn, unsigned int *rrbp);
 void tbf_set_polling(struct gprs_rlcmac_tbf *tbf, uint32_t new_poll_fn, uint8_t ts, enum pdch_ulc_tbf_poll_reason t);
 void tbf_poll_timeout(struct gprs_rlcmac_tbf *tbf, struct gprs_rlcmac_pdch *pdch, uint32_t poll_fn, enum pdch_ulc_tbf_poll_reason reason);
 void tbf_update_state_fsm_name(struct gprs_rlcmac_tbf *tbf);
@@ -188,9 +188,6 @@
 	void t_stop(enum tbf_timers t, const char *reason);
 	void t_start(enum tbf_timers t, int T, const char *reason, bool force,
 		     const char *file, unsigned line);
-
-	int check_polling(uint32_t fn, uint8_t ts,
-		uint32_t *poll_fn, unsigned int *rrbp) const;
 	void set_polling(uint32_t poll_fn, uint8_t ts, enum pdch_ulc_tbf_poll_reason reason);
 	void poll_timeout(struct gprs_rlcmac_pdch *pdch, uint32_t poll_fn, enum pdch_ulc_tbf_poll_reason reason);
 
diff --git a/src/tbf_dl.cpp b/src/tbf_dl.cpp
index 9214aae..25aea48 100644
--- a/src/tbf_dl.cpp
+++ b/src/tbf_dl.cpp
@@ -803,7 +803,7 @@
 				  POLL_ACK_AFTER_FRAMES);
 		}
 
-		rc = check_polling(fn, pdch->ts_no, &new_poll_fn, &rrbp);
+		rc = tbf_check_polling(this, pdch, fn, &new_poll_fn, &rrbp);
 		if (rc >= 0) {
 			set_polling(new_poll_fn, pdch->ts_no, PDCH_ULC_POLL_DL_ACK);
 			LOGPTBFDL(this, LOGL_DEBUG,
diff --git a/src/tbf_dl_ass_fsm.c b/src/tbf_dl_ass_fsm.c
index 207e4d3..6a1bc92 100644
--- a/src/tbf_dl_ass_fsm.c
+++ b/src/tbf_dl_ass_fsm.c
@@ -61,7 +61,7 @@
 	/* We only use this function in control TS (PACCH) so that MS can always answer the poll */
 	OSMO_ASSERT(tbf_is_control_ts(ctx->tbf, d->pdch));
 
-	rc = tbf_check_polling(ctx->tbf, d->fn, d->pdch->ts_no, &new_poll_fn, &rrbp);
+	rc = tbf_check_polling(ctx->tbf, d->pdch, d->fn, &new_poll_fn, &rrbp);
 	if (rc < 0)
 		return NULL;
 
diff --git a/src/tbf_ul_ack_fsm.c b/src/tbf_ul_ack_fsm.c
index 9501190..a188b08 100644
--- a/src/tbf_ul_ack_fsm.c
+++ b/src/tbf_ul_ack_fsm.c
@@ -59,7 +59,7 @@
 	struct GprsMs *ms = tbf_ms(ul_tbf_as_tbf(tbf));
 
 	if (final) {
-		rc = tbf_check_polling(ul_tbf_as_tbf(tbf), d->fn, d->pdch->ts_no, &new_poll_fn, &rrbp);
+		rc = tbf_check_polling(ul_tbf_as_tbf(tbf), d->pdch, d->fn, &new_poll_fn, &rrbp);
 		if (rc < 0)
 			return NULL;
 	}
diff --git a/src/tbf_ul_ass_fsm.c b/src/tbf_ul_ass_fsm.c
index d910095..8f2b70c 100644
--- a/src/tbf_ul_ass_fsm.c
+++ b/src/tbf_ul_ass_fsm.c
@@ -83,7 +83,7 @@
 	unsigned int rrbp;
 	uint32_t new_poll_fn;
 
-	rc = tbf_check_polling(ctx->tbf, d->fn, d->pdch->ts_no, &new_poll_fn, &rrbp);
+	rc = tbf_check_polling(ctx->tbf, d->pdch, d->fn, &new_poll_fn, &rrbp);
 	if (rc < 0)
 		return NULL;