RegDomain issues with setting up 5GHz AP with ath9k - recommendations?

[Michal Zatloukal]

Hi,
I'm trying to set up a 5GHz network with an ath9k card from a laptop
- AR5BHB112 (half-length minicard with AR9380). Hostapd reports that the
driver refuses to set AP mode in any 5GHz band I tried. From researching
this issue, this is because the card's firmware is set to "world"
regdomain (0x60), which prohibits self-initiated transmissions on
5GHz. From what
I understand, my options are to:
- either patch the ath9k driver to ignore the firmware' regdomain info and
just leave regulatory compliance to crda,
- or flash the wifi card to set a different regdomain for 5GHz
(probably country-specific, or null?)

Which option would you recommend? The machine is an all-purpose x86-64
server running ubuntu LTS, so kernel updates are somewhat common and I'd
hate to have to manually recompile a patched ath9k with every kernel
update, and worry how long the patch will remain functional. On the
other hand, it seems no one on the Internet has managed to mod the
firmware of AR9003-based cards. Links to any helpful guides/howto
would be greatly appreciated.

Regards,
MZ