trxcon/trx_if.c: drop Timing Advance range limitation

Despite the correct range of Timing Advance value is [0..63],
there is a special feature in OsmocomBB which allows one to
simulate the distance between both MS and a BTS by playing
with the signal delay.

This is why a signed 'int8_t' type is used in L1CTL protocol.
No need to limit the range, just forward it to TRX.

Change-Id: I06774b315b8451bf14083da6b2849d6e8594abc8

1 files changed, 3 insertions, 7 deletions

diff --git a/src/host/trxcon/trx_if.c b/src/host/trxcon/trx_if.c
index b3735c2b..19d8c753 100644
--- a/src/host/trxcon/trx_if.c
+++ b/src/host/trxcon/trx_if.c
@@ -380,7 +380,9 @@ static void trx_if_measure_rsp_cb(struct trx_instance *trx, char *resp)
  * advance calculated from requested TA value. This value is
  * normally between 0 and 63, with each step representing
  * an advance of one bit period (about 3.69 microseconds).
- * CMD SETTA <0-63>
+ * Since OsmocomBB has a special feature, which allows one
+ * to spoof the distance from BTS, the range is extended.
+ * CMD SETTA <-128..127>
  * RSP SETTA <status> <TA>
  */
 
@@ -390,12 +392,6 @@ int trx_if_cmd_setta(struct trx_instance *trx, int8_t ta)
 	if (trx->ta == ta)
 		return 0;
 
-	/* Make sure that TA value is in valid range */
-	if (ta < 0 || ta > 63) {
-		LOGP(DTRX, LOGL_ERROR, "TA value %d is out of allowed range\n", ta);
-		return -ENOTSUP;
-	}
-
 	return trx_ctrl_cmd(trx, 0, "SETTA", "%d", ta);
 }