Hello all -
I have been into testing and finding wireless drivers that do the trick in ad-hoc mode for quite a while. Linux has made great progress with this regard. Since 2.6.31 you can fix the cell-id with the command
iwconfig <interface> ap 01:CA:FF:EE:BA:BE
Actually I have seen Linux-wireless drivers work properly in ad-hoc mode before station mode became stable (who needs station mode if you have proper ad-hoc mode, anyway ;-) For anything supported by recent Linux-Wireless drivers chances are that ad-hoc works flawlessly. (As long as there are no binary-only firmware bugs...)
Hall of fame: (Not a complete list, add your favorite drivers, if you have a solution for problems mentioned here, please share, some info I'm providing may be outdated)
Atheros 802.11abg with Openwrt version of Madwifi driver (note that the vanilla Madwifi does not work) Supports ahdemo mode, and range/MAC timing settings, and many other cool things. Only supports PCI/PCIe/Cardbus - no USB
ath5k (Atheros 802.11abg) - use a recent version of the Linux kernel >2.6.28 and compile the newest compat-wireless sources against it - no USB
ath9k (Atheros 802.11abgn) - use a recent version of the Linux kernel >2.6.28 and compile the newest compat-wireless sources against it - no USB
iwlagn (Intel 4965) - I have this card in a Lenovo T61, works excellent, but there is a problem with suspend/resume (driver/card doesn't wake up properly, so I unload/reload the driver) Haven't updated the driver recently, may be already fixed in recent compat-wireless
Working, but some issues:
Everything USB-based that I know has at least one problem :-| Some stability issues may only occur if you have a mix of different drivers/hardware in your mesh.
rt73 - kind of works, but AFAIK there are problems with the ad-hoc neighbor station speed table. Problem is firmware/hardware related AFAIK - closed source firmware.
zd1211rw - Zydas chipset, now property of Atheros - not fully stable in my tests, seems to be firmware related - closed source firmware. Also problems with ad-hoc neighbor speed table.
ar9170usb - Atheros 802.11abgn USB - a promising candidate, open source firmware, driver development in a relatively early stage and therefore probably not stable yet. I'm currently testing it some more. Expensive.
Looking forward to your additions/corrections. I'm very much looking forward to get the first proper working USB driver! Would be brilliant to have!
Cheers, Elektra