Loop in bitforce scanhash till end nonce reaches full nonce range.

driver-bitforce.c

@@ -420,8 +420,9 @@ static uint64_t bitforce_scanhash(struct thr_info *thr, struct work *work, uint6
 	struct cgpu_info *bitforce = thr->cgpu;
 	unsigned int sleep_time;
 	struct timeval tdiff;
-	uint64_t ret;
+	uint64_t ret = 1;
 
+	while (bitforce->end_nonce < 0xffffffff) {
 		bitforce->wait_ms = 0;
 		ret = bitforce_send_work(thr, work);
 
@@ -457,13 +458,14 @@ static uint64_t bitforce_scanhash(struct thr_info *thr, struct work *work, uint6
 			ret = bitforce_get_result(thr, work);
 
 		if (!ret) {
-		ret = 1;
 			applog(LOG_ERR, "BFL%i: Comms error", bitforce->device_id);
 			bitforce->device_last_not_well = time(NULL);
 			bitforce->device_not_well_reason = REASON_DEV_COMMS_ERROR;
 			bitforce->dev_comms_error_count++;
 			/* empty read buffer */
 			biforce_clear_buffer(bitforce);
+			return 1;
+		}
 	}
 	return ret;
 }