Is FreeBSD -CURRENT sata port multiplier support functional yet?

Is FreeBSD -CURRENT sata port multiplier support functional yet?

I just tried the 8.0-CURRENT-200812-amd64-dvd1.iso snapshot on a Dell
435MT (Core i7) with a generic Silicon Image 3132 card (three different
cards actually) and two Sans Digital eSATA enclosures that were tested
to work OK with a Macintosh before & after the FreeBSD test.

It appears the port multiplier is detected but that FreeBSD is not able
to probe the disks behind the port multiplier.

ata2 below has the port multiplier enclosure attached.  There are disks
in the 0 and 1 slots in the enclosure.  The disk in slot 0 is detected
by the 3132 option ROM.  The enclosure and all slots work fine on a
Macintosh with the Silicon Image drivers.  The boot disk on ata4 is on
an Intel chip.

atapci0: <SiI 3132 SATA300 controller> port 0xcc00-0xcc7f mem
0xfbcffc00-0xfbcffc7f,0xfbcf8000-0xfbcfbfff irq 16 at device 0.0 on pci2
atapci0: Reserved 0x80 bytes for rid 0x20 type 4 at 0xcc00
atapci0: [MPSAFE]
atapci0: [ITHREAD]
atapci0: Reserved 0x80 bytes for rid 0x10 type 3 at 0xfbcffc00
atapci0: Reserved 0x4000 bytes for rid 0x18 type 3 at 0xfbcf8000
ata2: <ATA channel 0> on atapci0
ata2: channel HW reset timeout
ata2: SATA connect status=00000000
ata2: phy reset found no device
ata2: [MPSAFE]
ata2: [ITHREAD]
ata3: <ATA channel 1> on atapci0
ata3: channel HW reset timeout
ata3: SATA connect status=00000000
ata3: phy reset found no device
ata3: [MPSAFE]
ata3: [ITHREAD]
...
ata2: identify ch->devices=00000000
ata3: identify ch->devices=00000000
ata4: identify ch->devices=00000001
firewire0: 1 nodes, maxhop <= 0, cable IRM = 0 (me)
firewire0: bus manager 0 (me)
ata2: CONNECT requested
ata4-master: pio=PIO4 wdma=WDMA2 udma=UDMA133 cable=40 wire
ad8: 476940MB <WDC WD5000AAKS-75A7B0 01.03B01> at ata4-master SATA300
ad8: 976773168 sectors [969021C/16H/63S] 16 sectors/interrupt 1 depth queue
GEOM: new disk ad8
spa_config_load:92[1]: Cannot open /boot/zfs/zpool.cache.
ZFS filesystem version 13
zvol_init:1167[1]: ZVOL Initialized.
ZFS storage pool version 13
ata2: CONNECTED
ata2: channel HW reset time=0ms
ata2: SATA connect time=0ms
ata2: siiprb_issue_cmd time=530ms status=00050000
ata2: SIGNATURE=96690101
ata2: siiprb_issue_cmd time=0ms status=00010000
ata2: siiprb_issue_cmd time=0ms status=00010000
ata2: siiprb_issue_cmd time=0ms status=00010000
ata2: SiI 3726 r1706 Portmultiplier with 5 ports
ata2: siiprb_issue_cmd time=0ms status=00010000
ata2: siiprb_issue_cmd time=0ms status=00010000
ata2: siiprb_issue_cmd time=0ms status=00010000
ata2: p0: connect time 0ms
ata2: siiprb_issue_cmd time=0ms status=00010000
ata2: p0: SIGNATURE=ffffffff
ata2: error writing PM port
ata2: p1: writing ATA_SC_DET_RESET failed
ata2: error writing PM port
ata2: p2: writing ATA_SC_DET_RESET failed
ata2: error writing PM port
ata2: p3: writing ATA_SC_DET_RESET failed
ata2: error writing PM port
ata2: p4: writing ATA_SC_DET_RESET failed
ata2: siiprb_reset devices=00008000
ata2: identify ch->devices=00008000
(probe0:sbp0:0:0:0): error 22
(probe0:sbp0:0:0:0): Unretryable Error
(probe1:sbp0:0:1:0): error 22
(probe1:sbp0:0:1:0): Unretryable Error
(probe2:sbp0:0:2:0): error 22
(probe2:sbp0:0:2:0): Unretryable Error
(probe3:sbp0:0:3:0): error 22
(probe3:sbp0:0:3:0): Unretryable Error
(probe4:sbp0:0:4:0): error 22
(probe4:sbp0:0:4:0): Unretryable Error
(probe5:sbp0:0:5:0): error 22
(probe5:sbp0:0:5:0): Unretryable Error
(probe6:sbp0:0:6:0): error 22
(probe6:sbp0:0:6:0): Unretryable Error
ad8: Intel check1 failed