Comment 111 for bug 34902

Info towards the rt2500 problem

The rt2500 driver for a PCI card
Network controller: RaLink RT2500 802.11g is without problem under Feisty on a Desktop system,
kernel 2.6.20-16-generic

BUT is troublesome on a Avertec 3200 laptop with a AMD K7 processor support:
powernow_k8 16064 0
cpufreq_stats 7360 0
cpufreq_userspace 5408 0
cpufreq_ondemand 9228 1
freq_table 5792 3 powernow_k8,cpufreq_stats,cpufreq_ondemand
cpufreq_powersave 2688 0
cpufreq_conservative 8200 0
-------

When hald tries to configure this intermal wireless card on bootup, there is near full processor utilization, and all else slows drastically, as others have reported. This situation is cured by:
$ sudo ifconfig ra0 down
or bypassed by blacklisting rt2500 so it is not loaded on boot up.

A path to a functional work around has been accidentally discovered, through not understood at all.
To achieve some wireless support, a D-link PCMCIA wireless card was tested. Its insertion drives loading of:
(from lsmod output)
ath_rate_sample
ath_pci
wlan 204868 4 wlan_scan_sta,ath_rate_sample,ath_pci
ath_hal 192592 3 ath_rate_sample,ath_pci

Surprisingly the, blacklisted rt2500 also loaded, with
$ ifconfig
reporting both ra0, ath0 and wifi0 blocks, For reasons obscure to me wifi0 always appears with ath0,
even on Systems without a Ralink card.
If someone can explain that it might apply towards the rt2500 problem

Most IMPORTANT, the concurrent rt2500 loading does not cause the previously mentioned resource drain.
This cooperativity only appears necessary during the initial r2500 + hardware setup phase.
Because the positive effect was retained even after:
$ sudo modprobe -r ath_rate_sample
$ sudo modprobe -r ath_pci
which unloads all ath related drivers, with ifconfig showing disappearence of ath0 and wifi0 blocks
The PCMCIA card can also be removed.

Subsequently:
$ sudo ifup ra0
with specification of essid and encryption key,
DOES establish the wireless connection and services were fine.

If some further tests,
$ sudo modprobe ath_pci
$ sudo modprobe ath_rate_sample
without D-link PCMCIA card insertion had the same beneficial effects,
when done before
$ sudo modprobe rt2500

/var/log/messages provides no usefull information at all, just the expected reports on hardware activation.oot

If I try removing and reinstalling drivers during a single bootup session the freeze situation occurs.
Again this is alleviated fully once there can be entered:
$ sudo ifconfig ra0 down

To summarize, on this paricular Averatec platform, setup of the RALINK wireless using rt2500 driver is facilitated by prior loading drivers supporting the PCMCIA card:
$ cardctl ident 0
  product info: "Atheros Communications, Inc.", "AR5001-0000-0000", "Wireless LAN Reference Card", "00"
  manfid: 0x0271, 0x0012
  function: 6 (network)

THough lacking sophistication in COMM code, I would be happy to interact with someone(s) ath_pci and rt2500 driver knowledgeable, to try to unravel these interactions/problem\