dmraid-45 problem with Intel 82801GR/GH

Hello,

i've tried to get dmraid working with my setup, which is an Intel ICH7
(fake)raid5 on Ubuntu 7.04.

RAID bus controller: Intel Corporation 82801GR/GH (ICH7 Family) Serial
ATA Storage Controller RAID (rev 01)

I've followed these instructions to get a patched kernel with the
dm-raid4-5 module:
https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.20/+bug/97655/comments/5

dmraid info:
root@Hypernode:~# dmraid -V
dmraid version:         1.0.0.rc13 (2006.10.11)
dmraid library version: 1.0.0.rc13 (2006.10.11)
device-mapper version:  4.11.0

root@Hypernode:~# dmraid -s
*** Group superset isw_chchibdjbf
--> Subset
name   : isw_chchibdjbf_StorageRaid
size   : 1170211328
stride : 128
type   : raid5_la
status : ok
subsets: 0
devs   : 3
spares : 0

root@Hypernode:~# dmraid -r
/dev/sda: isw, "isw_chchibdjbf", GROUP, ok, 586114701 sectors, data@ 0
/dev/sdb: isw, "isw_chchibdjbf", GROUP, ok, 586114701 sectors, data@ 0
/dev/sdc: isw, "isw_chchibdjbf", GROUP, ok, 586114701 sectors, data@ 0


The initscript supplied with the dmraid ubuntu package modprobes dm-mod only,
so i've added modprobe dm-raid4-5 one line below. After loading those modules,
the script executes dmraid --activate yes --ignorelocking, which failed
resulting in locking up the machine.

Here is what i've found in the syslog afterwards:

  [  247.038792] raid5: automatically using best checksumming
function: pIII_sse
  [  247.054921]    pIII_sse  :  4015.000 MB/sec
  [  247.054925] raid5: using function: pIII_sse (4015.000 MB/sec)
  [  247.099256] device-mapper: dm-raid45: : initialized v0.1444
  [  254.728204] device-mapper: dm-raid45: : /dev/sda is raid disk 0
  [  254.728210] device-mapper: dm-raid45: : /dev/sdc is raid disk 1
  [  254.728214] device-mapper: dm-raid45: : /dev/sdb is raid disk 2
  [  254.728221] device-mapper: dm-raid45: : 128/128 sectors chunk/io
size and 64 stripes
  [  254.728225] device-mapper: dm-raid45: : algorithm "xor_asm", 2
chunks with 5261MB/s
  [  254.728228] device-mapper: dm-raid45: : RAID5 (left asymmetric)
set with net 2/3 devices
  [  254.728336] BUG: unable to handle kernel NULL pointer dereference
at virtual address 00000008
  [  254.728343]  printing eip:
  [  254.728345] c01301ce
  [  254.728347] *pde = 00000000
  [  254.728350] Oops: 0002 [#1]
  [  254.728352] SMP
  [  254.728356] Modules linked in: dm_raid4_5 dm_region_hash
dm_mem_cache xor ppdev capability commoncap cpufreq_powersave
cpufreq_userspace cpufreq_stats cpufreq_ondemand freq_table
cpufreq_conservative tc1100_wmi dev_acpi pcc_acpi sony_acpi video
button sbs i2c_ec i2c_core battery asus_acpi backlight dock container
ac nls_utf8 ntfs ipv6 sbp2 lp fuse snd_emu10k1_synth snd_emux_synth
snd_seq_virmidi snd_seq_midi_emul snd_emu10k1 snd_ac97_codec ac97_bus
snd_pcm_oss snd_mixer_oss snd_hda_intel snd_hda_codec snd_mpu401
snd_mpu401_uart snd_pcm snd_util_mem snd_hwdep snd_seq_dummy
snd_seq_oss snd_seq_midi snd_rawmidi xpad snd_seq_midi_event snd_seq
sk98lin analog pcspkr psmouse snd_timer snd_seq_device iTCO_wdt
iTCO_vendor_support b1pci b1dma b1 serio_raw parport_pc parport snd
kernelcapi af_packet shpchp pci_hotplug soundcore snd_page_alloc
emu10k1_gp gameport tsdev evdev ext3 jbd mbcache dm_mirror dm_log
dm_mod sr_mod cdrom ata_generic sg sd_mod usbhid hid ata_piix
pata_it821x ohci139
   ahci libata scsi_mod floppy ehci_hcd ieee1394 skge e1000 generic
uhci_hcd usbcore thermal processor fan
  [  254.728467] CPU:    1
  [  254.728468] EIP:    0060:[try_to_del_timer_sync+46/80]    Not tainted VLI
  [  254.728470] EFLAGS: 00010086   (2.6.20.3-ubuntu1 #1)
  [  254.728480] EIP is at try_to_del_timer_sync+0x2e/0x50
  [  254.728484] eax: 00000008   ebx: f7ebbc54   ecx: f7ebbc01   edx: f8dff000
  [  254.728488] esi: 00000001   edi: f7ebbc44   ebp: df1ac380   esp: f4903da0
  [  254.728494] ds: 007b   es: 007b   ss: 0068
  [  254.728497] Process dmraid (pid: 6165, ti=f4902000 task=f43ce030
task.ti=f4902000)
  [  254.728500] Stack: 00000282 f7ebbc54 00000000 c01301fe f7ebbc00
f8de4b3d 00000000 df1ac380
  [  254.728509]        df1ac380 f8ddf18b f89c2f59 df1ac280 ffffffea
f89c2502 00000000 df1ac280
  [  254.728522]        f8df2000 f89c5ac7 f4903e24 fffffff4 f8df2000
00000006 f4903e24 f89c6480
  [  254.728531] Call Trace:
  [  254.728545]  [del_timer_sync+14/32] del_timer_sync+0xe/0x20
  [  254.728554]  [<f8de4b3d>] wake_do_raid_delayed+0x1d/0x60 [dm_raid4_5]
  [  254.728575]  [<f8ddf18b>] rh_start_recovery+0x2b/0x30 [dm_region_hash]
  [  254.728588]  [<f89c2f59>] dm_table_resume_targets+0x69/0x80 [dm_mod]
  [  254.728615]  [<f89c2502>] dm_resume+0x82/0x100 [dm_mod]
  [  254.728644]  [<f89c5ac7>] dev_suspend+0x137/0x1b0 [dm_mod]
  [  254.728679]  [<f89c6480>] ctl_ioctl+0x220/0x290 [dm_mod]
  [  254.728701]  [__alloc_pages+79/832] __alloc_pages+0x4f/0x340
  [  254.728718]  [mntput_no_expire+36/160] mntput_no_expire+0x24/0xa0
  [  254.728730]  [<f89c5990>] dev_suspend+0x0/0x1b0 [dm_mod]
  [  254.728989]  [do_ioctl+120/144] do_ioctl+0x78/0x90
  [  254.729014]  [vfs_ioctl+92/672] vfs_ioctl+0x5c/0x2a0
  [  254.729040]  [sys_ioctl+114/144] sys_ioctl+0x72/0x90
  [  254.729061]  [sysenter_past_esp+105/169] sysenter_past_esp+0x69/0xa9
  [  254.729128]  =======================
  [  254.729131] Code: ff ff ff 53 89 c3 83 ec 04 89 e2 e8 9d ff ff ff
3b 58 04 89 c1 74 23 8b 03 31 f6 85 c0 74 1b 8b 13 66 be 01 00 8b 43
04 89 42 04 <89> 10 c7 43 04 00 02 20 00 c7 03 00 00 00 00 8b 14 24 89
c8 e8
  [  254.729181] EIP: [try_to_del_timer_sync+46/80]
try_to_del_timer_sync+0x2e/0x50 SS:ESP 0068:f4903da0

I hope that i've provided all necessary information for pinning this
down, if not, please let me know.

I appreciate your help