Laptop freezes when adjusting brightness (Fresh Install)

[Ken Simon]

I recently did a fresh install of ubuntu on my Fujitsu s2020 notebook.
Adjusting brightness with the Fn+F[6-7] keys hard locks the system instantly,
100% of the time. I have the feeling this is an ACPI problem, so I post it
here. It does it as soon as the kernel loads, as well. Pressing the brightness
keys after the first second or two after grub launches ubuntu causes it to
freeze. I have a feeling that disabling ACPI support from the kernel will solve
this problem, but I will miss out on a lot of features.

Some stuff from /proc/acpi:
ken@carrot:/proc/acpi $ cat `find .` | grep -v 'Is a directory'
state: open
type: Lid Switch
type: Power Button (FF)
state: on-line
alarm: unsupported
present: yes
capacity state: ok
charging state: discharging
present rate: 0 mA
remaining capacity: 3400 mAh
present voltage: 12514 mV
present: yes
design capacity: 3400 mAh
last full capacity: 3400 mAh
battery technology: rechargeable
design voltage: 10800 mV
design capacity warning: 0 mAh
design capacity low: 0 mAh
capacity granularity 1: 1 mAh
capacity granularity 2: 1 mAh
model number: CP144820-XX / CP144821-XX
serial number: 2
battery type: LION
OEM info: Fujitsu
alarm: unsupported
present: yes
capacity state: ok
charging state: discharging
present rate: 0 mA
remaining capacity: 3420 mAh
present voltage: 12179 mV
present: yes
design capacity: 3800 mAh
last full capacity: 3800 mAh
battery technology: rechargeable
design voltage: 10800 mV
design capacity warning: 0 mAh
design capacity low: 0 mAh
capacity granularity 1: 1 mAh
capacity granularity 2: 1 mAh
model number: CP147685-XX / CP147686-XX
serial number: 1
battery type: LION
OEM info: Fujitsu
<not supported>
<not supported>
active state: C2
default state: C1
bus master activity: 00000000
states:
    C1: promotion[C2] demotion[--] latency[000] usage[00088780]
  *C2: promotion[--] demotion[C1] latency[090] usage[02546800]
   C3: <not supported>
processor id: 0
acpi id: 0
bus mastering control: yes
power management: yes
throttling control: no
limit interface: no
Device Sleep state Status
PCI0 4 disabled
UAR1 3 disabled
 LID 4 *enabled
2004-11-29 11:01:55
S0 S3 S4 S5
version: 20040816

ken@carrot:/proc/acpi $ lsmod
Module Size Used by
sd_mod 20480 0
usb_storage 59200 0
scsi_mod 115148 2 sd_mod,usb_storage
proc_intf 3968 0
freq_table 4356 0
cpufreq_userspace 5336 0
cpufreq_powersave 2048 0
ipv6 230020 12
ds 17796 4
button 6936 0
ac 5132 0
battery 9740 0
af_packet 20872 2
ehci_hcd 27780 0
ohci_hcd 19460 0
usbcore 104292 5 usb_storage,ehci_hcd,ohci_hcd
ohci1394 32004 0
ieee1394 100536 1 ohci1394
8139too 23936 0
8139cp 19072 0
mii 4864 2 8139too,8139cp
crc32 4608 2 8139too,8139cp
ath_pci 49824 0
ath_rate_onoe 8456 1 ath_pci
wlan 105308 3 ath_pci,ath_rate_onoe
ath_hal 133200 2 ath_pci
yenta_socket 19328 0
pcmcia_core 63156 2 ds,yenta_socket
snd_ali5451 22728 3
snd_ac97_codec 59268 1 snd_ali5451
snd_pcm_oss 48168 0
snd_mixer_oss 16640 3 snd_pcm_oss
snd_pcm 85540 2 snd_ali5451,snd_pcm_oss
snd_page_alloc 11144 1 snd_pcm
snd_timer 23172 1 snd_pcm
snd 50660 8
snd_ali5451,snd_ac97_codec,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_timer
soundcore 9824 3 snd
pci_hotplug 30640 0
ati_agp 8332 1
agpgart 31784 1 ati_agp
irtty_sir 8320 0
sir_dev 18092 1 irtty_sir
irda 167360 2 irtty_sir,sir_dev
crc_ccitt 2432 1 irda
pcspkr 3816 0
rtc 12216 0
nls_iso8859_1 4352 1
nls_cp437 6016 1
vfat 13312 1
fat 41792 1 vfat
md 44744 0
dm_mod 51068 1
capability 4872 0
commoncap 7168 1 capability
parport_pc 32064 1
lp 10436 0
parport 37320 2 parport_pc,lp
ide_cd 38276 0
cdrom 35872 1 ide_cd
tsdev 7168 0
evdev 9088 0
mousedev 10124 1
psmouse 17800 0
xfs 500184 1
ext3 109544 1
jbd 54552 1 ext3
ide_generic 1664 0
ide_disk 16768 5
alim15x3 11404 1
ide_core 125272 5
usb_storage,ide_cd,ide_generic,ide_disk,alim15x3unix 25904 762
fan 4236 0
thermal 13200 0
processor 17712 1 thermal
font 8576 0
vesafb 6688 0
cfbcopyarea 3968 1 vesafb
cfbimgblt 3200 1 vesafb
cfbfillrect 3712 1 vesafb

Searching the web doesn't return anything, I can't find anything related to
crashing when adjusting brightness.

[Matt Zimmerman (mdz)]

Can you try the kernel available here:

http://www.ubuntulinux.org/wiki/PMTesting

and see if it fixes your problem?

[Ken Simon (ninkendo)]

Yes, that fixes it just fine, thanks!

Unfortunately though, there is no linux-source-2.6.9 deb available from the repo
listed on that site, so I can't customize my kernel at all. (That is not to say
that I was customizing the kernel that was giving me the ACPI trouble. The
brightness freezing issue occured even during install.) Is there a way I can
get my hands on the tarball/deb for the kernel source? Or is it pretty much
vanilla? Any help would be appreciated, thanks a lot!

[Matthew Garrett (mjg59)]

Is this fixed in Hoary?

[Matthew Garrett (mjg59)]

The code from that kernel is in the distribution now.