When I ported mlphy(4) from freebsd, I only tested on i386. It's safer to disable it on alpha until testers show up. I don't own an alpha either.
Index: RAMDISKBIG =================================================================== RCS file: /cvs/src/sys/arch/alpha/conf/RAMDISKBIG,v retrieving revision 1.84 diff -u -r1.84 RAMDISKBIG --- RAMDISKBIG 29 Jun 2011 20:52:08 -0000 1.84 +++ RAMDISKBIG 21 Jul 2011 17:52:28 -0000 @@ -235,7 +235,7 @@ rgephy* at mii? # Realtek 8169S/8110S PHY ciphy* at mii? # Cicada CS8201 10/100/1000 copper PHY ipgphy* at mii? # IC Plus IP1000A PHYs -mlphy* at mii? # Micro Linear 6692 PHY +#mlphy* at mii? # Micro Linear 6692 PHY ukphy* at mii? # "unknown" PHYs # ISA/EISA bus support Index: GENERIC =================================================================== RCS file: /cvs/src/sys/arch/alpha/conf/GENERIC,v retrieving revision 1.224 diff -u -r1.224 GENERIC --- GENERIC 7 Jul 2011 23:41:09 -0000 1.224 +++ GENERIC 21 Jul 2011 17:52:29 -0000 @@ -283,7 +283,7 @@ rgephy* at mii? # Realtek 8169S/8110S PHY ciphy* at mii? # Cicada CS8201 10/100/1000 copper PHY ipgphy* at mii? # IC Plus IP1000A PHYs -mlphy* at mii? # Micro Linear 6692 PHY +#mlphy* at mii? # Micro Linear 6692 PHY ukphy* at mii? # "unknown" PHYs # sensors