Index: head/sys/dev/sfxge/common/efx_lic.c
===================================================================
--- head/sys/dev/sfxge/common/efx_lic.c
+++ head/sys/dev/sfxge/common/efx_lic.c
@@ -1010,27 +1010,15 @@
 {
 	efx_mcdi_req_t req;
 	EFX_MCDI_DECLARE_BUF(payload, MC_CMD_LICENSING_GET_ID_V3_IN_LEN,
-		MC_CMD_LICENSING_GET_ID_V3_OUT_LENMIN);
+		MC_CMD_LICENSING_GET_ID_V3_OUT_LENMAX);
 	efx_rc_t rc;
 
 	req.emr_cmd = MC_CMD_LICENSING_GET_ID_V3;
+	req.emr_in_buf = payload;
+	req.emr_in_length = MC_CMD_LICENSING_GET_ID_V3_IN_LEN;
+	req.emr_out_buf = payload;
+	req.emr_out_length = MC_CMD_LICENSING_GET_ID_V3_OUT_LENMAX;
 
-	if (bufferp == NULL) {
-		/* Request id type and length only */
-		req.emr_in_buf = bufferp;
-		req.emr_in_length = MC_CMD_LICENSING_GET_ID_V3_IN_LEN;
-		req.emr_out_buf = bufferp;
-		req.emr_out_length = MC_CMD_LICENSING_GET_ID_V3_OUT_LENMIN;
-	} else {
-		/* Request full buffer */
-		req.emr_in_buf = bufferp;
-		req.emr_in_length = MC_CMD_LICENSING_GET_ID_V3_IN_LEN;
-		req.emr_out_buf = bufferp;
-		req.emr_out_length =
-		    MIN(buffer_size, MC_CMD_LICENSING_GET_ID_V3_OUT_LENMAX);
-		(void) memset(bufferp, 0, req.emr_out_length);
-	}
-
 	efx_mcdi_execute_quiet(enp, &req);
 
 	if (req.emr_rc != 0) {
@@ -1047,19 +1035,10 @@
 	*lengthp =
 	    MCDI_OUT_DWORD(req, LICENSING_GET_ID_V3_OUT_LICENSE_ID_LENGTH);
 
-	if (bufferp == NULL) {
-		/*
-		 * Modify length requirements to indicate to caller the extra
-		 * buffering needed to read the complete output.
-		 */
-		*lengthp += MC_CMD_LICENSING_GET_ID_V3_OUT_LENMIN;
-	} else {
-		/* Shift ID down to start of buffer */
-		memmove(bufferp,
-		    bufferp + MC_CMD_LICENSING_GET_ID_V3_OUT_LICENSE_ID_OFST,
-		    *lengthp);
-		memset(bufferp + (*lengthp), 0,
-		    MC_CMD_LICENSING_GET_ID_V3_OUT_LICENSE_ID_OFST);
+	if (bufferp != NULL) {
+		memcpy(bufferp,
+		    payload + MC_CMD_LICENSING_GET_ID_V3_OUT_LICENSE_ID_OFST,
+		    MIN(buffer_size, *lengthp));
 	}
 
 	return (0);