[PATCH] WLAN: --power maxperf shot into the dark

[John Sullivan]

Werner Almesberger <werner at openmoko.org> writes:

> John Sullivan wrote:
>> What was happening for me is that I got a lease and could do dns lookups
>> but could not ping the gateway or any other host -- there would be one
>> ping attempt that did not return.
>
> Hmm, that's very odd. There shouldn't really be a difference between
> DHCP, DNS, and ping - at least not one that goes away if you use
> --power maxperf. Perhaps this depends also on time. Do DHCP and DNS
> continue to work after you had ping failures ?
>

They do continue to work, yes.

> It would be interesting to know what your WLAN environment looks like
> (iwlist scan) and what "iwconfig eth0" says while you're experiencing
> this sort of problems. Also, if you know anything about the access
> point(s), such as brand or firmware, that would be useful.
>

Well, you're right. Even without the maxperf set, I can connect just
fine to a Fon router. But at home, I can't ping my Verizon FiOS router,
which is a coax MI424-WR.

> One known issue is that the AR6k sometimes tunes to the wrong
> frequency for some reason, which could explain lossy communication.
>

I am seeing some oddness in the frequencies. My laptop connected to this
router says frequency 2.422 GHz. But the FR says 2.417 GHz. But then, I
change the channel on the router to channel 3, and the FR sets to 2.422
GHz, which is the same as what iwconfig on the laptop says, but the FR
still doesn't work. Link quality is also... weird. Here is some info
from the FR:

root at calvino:~# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:12:cf:8f:36:ac
          inet addr:192.168.1.6  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::212:cfff:fe8f:36ac/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:5808 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1742 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:2667443 (2.5 MiB)  TX bytes:158789 (155.0 KiB)

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:36340 errors:0 dropped:0 overruns:0 frame:0
          TX packets:36340 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:2856303 (2.7 MiB)  TX bytes:2856303 (2.7 MiB)

root at calvino:~# iwconfig eth0
eth0      AR6000 802.11g  ESSID:"wjsullivan.net"
          Mode:Managed  Frequency:2.412 GHz  Access Point: 00:18:01:FD:1C:F5
          Bit Rate=54 Mb/s   Tx-Power=15 dBm   Sensitivity=0/3
          Retry:on
          Encryption key:off
          Power Management:off
          Link Quality:204/94  Signal level:-147 dBm  Noise level:-96 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:31  Invalid misc:0   Missed beacon:124

root at calvino:~# iwlist eth0 scanning
eth0      Scan completed :
          Cell 01 - Address: 00:21:29:9A:94:19
                    ESSID:"jmorgen"
                    Mode:Master
                    Frequency:2.437 GHz (Channel 6)
                    Quality=3/94  Signal level=-92 dBm  Noise level=-95 dBm
                    Encryption key:on
                    Extra:bcn_int=100
                    Extra:wpa_ie=dd180050f20101000050f20201000050f20201000050f2020000
          Cell 02 - Address: 00:18:01:FB:17:87
                    ESSID:"LAMW6"
                    Mode:Master
                    Frequency:2.412 GHz (Channel 1)
                    Quality=46/94  Signal level=-49 dBm  Noise level=-95 dBm
                    Encryption key:on
                    Extra:bcn_int=100
                    Extra:wmm_ie=dd180050f2020101020003a4000027a4000042435e0062322f00
                    Extra:ath_ie=dd0900037f010100200000
          Cell 03 - Address: 00:18:01:EF:A8:07
                    ESSID:"L86S2"
                    Mode:Master
                    Frequency:2.412 GHz (Channel 1)
                    Quality=4/94  Signal level=-91 dBm  Noise level=-95 dBm
                    Encryption key:on
                    Extra:bcn_int=100
                    Extra:wmm_ie=dd180050f2020101020003a4000027a4000042435e0062322f00
                    Extra:ath_ie=dd0900037f010100200000
          Cell 04 - Address: 00:18:01:E7:A2:D0
                    ESSID:"N3061"
                    Mode:Master
                    Frequency:2.462 GHz (Channel 11)
                    Quality=11/94  Signal level=-84 dBm  Noise level=-95 dBm
                    Encryption key:on
                    Extra:bcn_int=100
          Cell 05 - Address: 00:18:01:FD:1C:F5
                    ESSID:"wjsullivan.net"
                    Mode:Master
                    Frequency:2.412 GHz (Channel 1)
                    Quality=39/94  Signal level=-56 dBm  Noise level=-95 dBm
                    Encryption key:off
                    Extra:bcn_int=100
                    Extra:wmm_ie=dd180050f20201010f0003a4000027a4000042435e0062322f00
                    Extra:ath_ie=dd0900037f01010020ff7f

root at calvino:~# ping gnu.org
PING gnu.org (199.232.41.10): 56 data bytes
^C--- gnu.org ping statistics ---
20 packets transmitted, 0 packets received, 100% packet loss
root at calvino:~# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 eth0
0.0.0.0         192.168.1.1     0.0.0.0         UG    0      0        0 eth0

root at calvino:~# cat /etc/resolv.conf
domain home
search home
nameserver 192.168.1.1