acpi_hp fails attach at boot

Hi

acpi_hp fails attach at boot, but if I load it manually in multi-user
it does attach.  I think this is because the acpi_hp module tries
to attach very early on before acpi_wmi which it depends on has
completed its attach:

[mini] ~ # grep ^acpi dmesg
acpi0: <061909 RSDT0044> on motherboard
acpi0: [ITHREAD]
acpi0: Power Button (fixed)
acpi_hp0: <HP ACPI-WMI Mapping> iomem 0xfed13000-0xfed19fff on acpi0
acpi_hp0: Couldn't find acpi_wmi device
acpi0: reservation of 0, a0000 (3) failed
acpi0: reservation of 100000, 7f700000 (3) failed
acpi_timer0: <24-bit timer at 3.579545MHz> port 0x808-0x80b on acpi0
acpi_hp0: <HP ACPI-WMI Mapping> iomem 0xfed13000-0xfed19fff on acpi0
acpi_hp0: Couldn't find acpi_wmi device
acpi_ec0: <Embedded Controller: GPE 0x17> port 0x62,0x66 on acpi0
acpi_hpet0: <High Precision Event Timer> iomem 0xfed00000-0xfed003ff on acpi0
acpi_button0: <Sleep Button> on acpi0
acpi_wmi0: <ACPI-WMI mapping> on acpi0
acpi_button1: <Power Button> on acpi0
acpi_tz0: <Thermal Zone> on acpi0
acpi_lid0: <Control Method Lid Switch> on acpi0
acpi_acad0: <AC Adapter> on acpi0

If I 'kldload acpi_hp' once the system is booted I get:

acpi_wmi0: <ACPI-WMI mapping> on acpi0
acpi_hp0: <HP ACPI-WMI Mapping> on acpi0
acpi_hp0: HP event GUID detected, installing event handler
acpi_hp0: HP CMI GUID detected

acpi_wmi obviously waits for the right time before it attempts to
probe or attach.  How can I make acpi_hp do the same?

Ian

--
Ian Freislich