4GB vs. 3945ABG -- kernel to blame

[tarvoke]

just some reference for others who may see the same issues...

picked up 2x2GB kit amazingly cheaply (here; sadly they've raised the price by $55, and started charging for shipping... wtf?! anyway....) and had no problems save wireless not working. er, not good.

bios does not offer any memory hole/remapping options as far as I can tell. and the bios startup/diagnostic screen only counts to 3062M for some reason. wtf santa rosa??!?

(naturally xp tablet 2005 only sees ~3GB of the memory)

amd64 kubuntu 7.10 sees all of the memory, but this is where the intel 3945 stopped working. it would always associate with the AP, but could never pull an IP address anymore. (wireless worked just fine in xp after the memory upgrade)

putting something like mem=2048M or mem=3062M into the grub menu actually fixed this, which made me think it's something about memory mapping for that particular driver.

tried booting a kubuntu 8.04t2 amd64 cd, and the 3945 wireless worked just fine. hm! newer kernel, newer 3945 driver module (iwl3945 evolution of ipw3945)

7.10 latest kernel is 2.6.22-14-generic. 8.04 (hardy) current kernel is 2.6.24-2-generic. to upgrade kernel only and keep gutsy/7.10 unchanged, you simply have to do something like this:
http://ubuntuforums.org/showthread.php?t=646755

which worked a treat and now I can have 4GB and wireless at the same time. (nb the caveat about wlan interface naming did bite me, and the suggested fix did not fix anything... but the only casualty is that my wlan led is not lighting up, ah well)

[dickeywang]

Thanks for sharing your experience. I am waiting for my 4GB to come. I am running Gutsy AMD64 on my T61p with a 4965abgn card. Let's see if I will have the same problem.

btw, I paid $80 for the same 2x2GB kit.

[tarvoke]

80 / free shipping was what I paid too. for a while it had gone up to 135 / non-free shipping, but sounds like they brought the deal back. nice.

I've since done the hardy kernel upgrade again, to 2.6.24-3; but the card still shows up as both eth1 and wlan0_rename. so still no wireless led. every other aspect is just fine. feels like the memory is dumping more heat than the stock ones, but that could just be in my head.

gonna try xp64 soon, heresy I know.