ath5k interrupt storm with linux 3.4.7 on IBM Thinkpad X31

Hi,

Linux 3.4.7 ath5k driver is unusable on a Thinkpad X31, the machine
uses almost 100% CPU handling interrupts, barely responding to
anything. Using the old version of the function ath5k_hw_get_isr() in
drivers/net/wireless/ath/ath5k/dma.c of Linux 3.1.6 patched into Linux
3.4.7 works again. My guess: some interrupt flags (0x400 and 0x80) are
not cleared correctly or retriggered artificially by some unlucky
register manipulations.

Enabling interrupt debug (debug=0x4 if a recall correctly) shows that
the interrupt status is stuck to 0x480 with Linux 3.4.7.

Is this a known problem ? Is there any detailed behaviour
description/documentation availabe of this chip ?

Cheers,
Manuel