diff --git a/sys/dev/cxgbe/common/t4_hw.c b/sys/dev/cxgbe/common/t4_hw.c
index bb2ed5e4d820..360d44847004 100644
--- a/sys/dev/cxgbe/common/t4_hw.c
+++ b/sys/dev/cxgbe/common/t4_hw.c
@@ -7740,9 +7740,18 @@ int t4_query_params_rw(struct adapter *adap, unsigned int mbox, unsigned int pf,
 	}
 
 	ret = t4_wr_mbox(adap, mbox, &c, sizeof(c), &c);
-	if (ret == 0)
-		for (i = 0, p = &c.param[0].val; i < nparams; i++, p += 2)
-			*val++ = be32_to_cpu(*p);
+
+	/*
+	 * We always copy back the results, even if there's an error.  We'll
+	 * get an error if any of the parameters was unknown to the Firmware,
+	 * but there will be results for the others ...  (Older Firmware
+	 * stopped at the first unknown parameter; newer Firmware processes
+	 * them all and flags the unknown parameters with a return value of
+	 * ~0UL.)
+	 */
+	for (i = 0, p = &c.param[0].val; i < nparams; i++, p += 2)
+		*val++ = be32_to_cpu(*p);
+
 	return ret;
 }