Test procedure:

1. Onboard 1394a chipset disabled (BIOS setting on Dell Inspiron 1420n laptop)
2. Blacklist all firewire modules
$ cat /etc/modprobe.d/blacklist-firewire.conf:
blacklist ohci1394
blacklist sbp2
blacklist dv1394
blacklist raw1394
blacklist video1394
blacklist firewire-ohci
blacklist firewire-sbp2
$ sudo update-initramfs -uk all
update-initramfs: Generating /boot/initrd.img-2.6.35-22-generic
update-initramfs: Generating /boot/initrd.img-2.6.32-24-generic

A.0)
$ uname -r
2.6.32-24-generic
$ sudo modprobe firewire-ohci
$ sudo modprobe firewire-sbp2
$ grep -E '1394|firewire' /proc/interrupts 
 19:          1          0   IO-APIC-fasteoi   firewire_ohci

A.1)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 17.3652 s, 30.9 MB/s
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts 
 19:       1187       1249   IO-APIC-fasteoi   firewire_ohci

A.2)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 17.383 s, 30.9 MB/s
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts 
 19:       2384       2512   IO-APIC-fasteoi   firewire_ohci

A.3)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 17.3679 s, 30.9 MB/s
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts
 19:       3751       3931   IO-APIC-fasteoi   firewire_ohci

A.4)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 17.3215 s, 31.0 MB/s
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts
 19:       4959       5151   IO-APIC-fasteoi   firewire_ohci

A.5)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 17.3445 s, 31.0 MB/s
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts
 19:       6147       6389   IO-APIC-fasteoi   firewire_ohci


###

B.0)
$ uname -r
2.6.32-24-generic
$ sudo modprobe ohci1394
$ sudo modprobe sbp2
$ grep -E '1394|firewire' /proc/interrupts
 19:          1          2   IO-APIC-fasteoi   ohci1394

B.1)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 17.3418 s, 31.0 MB/s
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts 
 19:       1408       1491   IO-APIC-fasteoi   ohci1394

B.2)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 17.3398 s, 31.0 MB/s
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts
 19:       2649       2756   IO-APIC-fasteoi   ohci1394

B.3)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 17.3447 s, 31.0 MB/s
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts
 19:       4042       4297   IO-APIC-fasteoi   ohci1394

B.4)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 17.3784 s, 30.9 MB/s
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts
 19:       5284       5582   IO-APIC-fasteoi   ohci1394

B.5)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 17.3365 s, 31.0 MB/s
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts
 19:       6563       6820   IO-APIC-fasteoi   ohci1394

C.0)
$ uname -r
2.6.35-22-generic
$ sudo modprobe firewire-ohci
$ sudo modprobe firewire-sbp2
$ grep -E '1394|firewire' /proc/interrupts
 19:          1          0   IO-APIC-fasteoi   firewire_ohci

C.1)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 479.353 s, 1.1 MB/s
# note: I/O errors filling up dmesg
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts
 19:      11079      10787   IO-APIC-fasteoi   firewire_ohci

C.2)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 479.36 s, 1.1 MB/s
# note: I/O errors filling up dmesg
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts
 19:      22419      21481   IO-APIC-fasteoi   firewire_ohci

C.3)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 478.916 s, 1.1 MB/s
# note: I/O errors filling up dmesg
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts
 19:      34181      33015   IO-APIC-fasteoi   firewire_ohci

C.4)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 479.282 s, 1.1 MB/s
# note: I/O errors filling up dmesg
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts
 19:      47516      46450   IO-APIC-fasteoi   firewire_ohci

C.5)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 479.314 s, 1.1 MB/s
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts
 19:      60834      59514   IO-APIC-fasteoi   firewire_ohci

D.0)
$ uname -r
2.6.35-22-generic
$ sudo modprobe ohci1394
$ sudo modprobe sbp2
$ grep -E '1394|firewire' /proc/interrupts
 19:          1          1   IO-APIC-fasteoi   ohci1394

D.1)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 17.2633 s, 31.1 MB/s
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts 
 19:       1277       1231   IO-APIC-fasteoi   ohci1394

D.2)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 17.2704 s, 31.1 MB/s
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts 
 19:       2498       2428   IO-APIC-fasteoi   ohci1394

D.3)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 17.288 s, 31.1 MB/s
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts 
 19:       4004       3968   IO-APIC-fasteoi   ohci1394

D.4)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 17.3277 s, 31.0 MB/s
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts 
 19:       5258       5170   IO-APIC-fasteoi   ohci1394

D.5)
# power on storage device
$ sudo dd if=/dev/zero bs=4k of=/dev/sdb count=128k
131072+0 records in
131072+0 records out
536870912 bytes (537 MB) copied, 17.268 s, 31.1 MB/s
# power off storage device
$ grep -E '1394|firewire' /proc/interrupts 
 19:       6477       6413   IO-APIC-fasteoi   ohci1394