When booting the generic 4.5 Release i386 kernel with a 160gb Maxtor
drive (4G160J8) attached to a Promise pdc20265r controller the 
kernel stops with trap 12. Bootdisk is a SCSI hardisk, there are no
other ata drives attached. When attaching the drive to ata3-master,
then boot -v shows:

...
ata2-master: ata_command: timeout waiting for intr
ata2-master: identify failed
ata3-master: success setting UDMA5 on Promise chip
Creating DISK ad6
ad6: <Maxtor 4G160J8/GAK819K0> ATA-6 disk at ata3-master
ad6: 156334MB (320173056 sectors), 317632 cyls, 16 heads, 63 S/T, 512 B/S
ad6: 16 secs/int, 1 dpth queue, UDMA100
ad6: piomode=4 dmamode=2 udmamode=6 cblid=1


Fatal trap12: page fault while in kernel mode
fault virtual address   = 0xa7
fault code              = supervisor read, page not present
instruction pointer     = 0x8:0xc030426a
stack pointer           = 0x10:0xc04b8704
frame pointer           = 0x10:0xc04b8724
code segment            = base rx0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 0 (swapper)
interrupt mask          =
trap number             = 12
panic: page fault

syncing disks...
done
Uptime: 20s
Automatic reboot in 15 seconds


Variations:
-----------

Setup: 
A naked system with graphics card, zero to two 3com 3c905ctx,
booting via SCSI disk a 4.5 Release, no other ata disks attached
except the 160gb Maxtor drive. The Promise does not share the IRQ
with other hardware.


WORKS = no problems when doing disklabel, newfs, mount and 
dd if=/dev/zero of='many megabytes' to the Maxtor disk

FAILS = boot fails as shown above

Asus A7V133 Via/Athlon with onboard Promise pdc20265r
   Maxtor  80G @ VIA (ad0..3)     : WORKS
   Maxtor 160G @ VIA (ad0..3)     : WORKS
   Maxtor  80G @ Promise (ad4..7) : WORKS
   Maxtor 160G @ Promise (ad4..7) : FAILS

Asus TUSL2 Intel i815E-B with onboard Promise pdc20265r
   Maxtor  80G @ Intel (ad0..3)   : WORKS
   Maxtor 160G @ Intel (ad0..3)   : WORKS
   Maxtor  80G @ Promise (ad4..7) : WORKS
   Maxtor 160G @ Promise (ad4..7) : FAILS

Abit KT133 Intel BX 440 with onboard Highpoint HPT 370
   Maxtor  80G @ Intel (ad0..3)     : WORKS
   Maxtor 160G @ Intel (ad0..3)     : WORKS
   Maxtor  80G @ Highpoint (ad4..7) : WORKS
   Maxtor 160G @ Highpoint (ad4..7) : WORKS

(Note: Although the Abit's name is KT133 it's a BX chipset)

It seems to be a problem with Promise and the new adressing
for disks > 130 GB (?)

Fix: 

sorry, no
How-To-Repeat: Connect a Maxtor 160G disk (4G160J8) to a Promise PDC20265R and 
boot the 4.5 Release GENERIC kernel