arcmsr + dmcrypt problem

arcmsr + dmcrypt problem

[Nikola Ciprich]

Hello everybody,
I've stumbled upon a problem with arcmsr driver: trying to use a dmcrypt 
encrypted volume on top of areca volume always hangs the card.

Steps to reproduce:

1) create some kind of raid on areca (raid5, or even a passthrough disc)
2) cryptsetup luksFormat /dev/sda1 (or whatever areca sdX device is)
3) cryptsetup luksOpen /dev/sda1 cryptotest
4) mkfs.xfs /dev/mapper/cryptotest
5) mount /dev/mapper/cryptotest /mnt/cryptotest
6) copy some data to /mnt/cryptotest

this hangs card and printk's following messages:
[  288.160614] arcmsr0: isr get an illegal ccb command done acb='0xffff810144758548'ccb='0xffff810020020000' ccbacb='0x50a05ed7588a40c0' startdone = 0xbcda ccboutstandingcount=1 --

I have tested it on:
1) SMP amd64 machine running 2.6.18 x86_64 kernel with external arcmsr 
module or 2.6.21.3 - it it always hangs on step 4
2) SMP xeon machine running 2.6.21 and also 2.6.22-rc6, UP or SMP, with 
acpi on or off, also tried disabling NCQ - always hangs on step 6

Card information:
Firmware Version   : V1.43 2007-4-17
BOOT ROM Version   : V1.43 2007-4-17
Controller Name    : ARC-1220

Apparently I'm not the first person to encounter this problem:
http://forums.storagereview.net/index.php?showtopic=25513

Should somebody be willing to hunt down this bug, I'd be more than happy 
to assist.

best regards

nik.