For MDADM, you don't need to select a RAID 4 parity disk explicitly

raid/CHANGELOG

@@ -5,3 +5,5 @@ Added a button for mounting a RAID device.
 RAID devices can now be easily mounted as virtual memory.
 ---- Changes since 1.280 ----
 Added support for RAID 6 arrays when using MDADM.
+---- Changes since 1.340 ----
+Removed need to explicitly select a parity disk for RAID 4 when using MDADM.

raid/raid_form.cgi

@@ -89,7 +89,7 @@ if ($lvl >= 4) {
 	print "</select></td> </tr>\n";
 	}
 
-if ($lvl == 4) {
+if ($lvl == 4 && $raid_mode ne 'mdadm') {
 	print "<tr> <td valign=top><b>$text{'create_pdisk'}</b></td>\n";
 	print "<td><select name=pdisk>\n";
 	print "<option value='' selected>$text{'create_auto'}\n";