wifi boot gets stuck (ath9k)

[carlos.alarcon]

Tests Run (summary)
Link detection (pass with errors)
Basic DHCP: pass
Close and reopen: pass
Large file transfer correctness: Fail (max HTTP file downloaded 250K, md5sum ok, any bigger file fails to downloada, and -t timeout seems not to work, since the command never ends)
Large file transfer speed: Not run
Link interruption: Not run
Loopback: Cannot imagine how to get that done
High-MTU loopback: idem
VLAN loopback: idem

Errors found in Link detection test:
5 Use ifstat to verify that the link state is reported as Up. Some networks (e.g. Infiniband) take a long time to reach link-up; you may have to wait several seconds.
it works (link is up) but errors it reports (the first time i run ifstat)
* http://ipxe.org/3c086003
* http://ipxe.org/380f6001
The second time, same errors and also:
* http://ipxe.org/440e6001
* http://ipxe.org/1c1f6603
6 Disconnect the network cable. (disable wifi)
7 Use ifstat to verify that the link state is reported as Down (or some more specific link error, if the driver uses netdev_link_err())
* link is reported as down
* Errors showed:
* http://ipxe.org/err/4c1f60
* http://ipxe.org/3c086003
* http://ipxe.org/380f6001
* http://ipxe.org/440e6001
* http://ipxe.org/1c1f6603
8 Reconnect the network cable. (enabled back the wifi)
9 Use ifstat to verify that the link state is again reported as Up.
* Link is reported back as up.
* Errors showed:
* http://ipxe.org/3c086003
* http://ipxe.org/380f6001
* http://ipxe.org/440e6001
* http://ipxe.org/1c1f6603