[ltp] T400 slow wifi connections

[Paul Marwick]

Joerg Mayer wrote:
>
> That's not what I wanted to say: If I read the specs correctly, the
> card has a theorectial max write speed that is half of its theorectial
> max read speed (1 transmit stream but 2 receive streams).

Ah. Reason I mentioned that was the 2.4 GHz connect is half the connect 
speed I used to see with my older (ADSL2) Linksys router.

> OK, so linux is using 40 MHz channels - I had expected to see only 20 
> MHz channels here. There goes my main suspect. 

:( Pity....

> Remaining ideas: On a (more or less freshly booted and associated system)
> do:
>
> dmesg | grep -E -i 'iwl|80211|wlan0'
> to see the kernel messages about the wifi setup and association, maybe there
> is something in there that catches the eye.
:( Ok. Much of it means very little to me, unfortunately:

[    7.145666] cfg80211: Calling CRDA to update world regulatory domain
[    7.656539] iwlwifi 0000:03:00.0: irq 47 for MSI/MSI-X
[    8.401384] cfg80211: World regulatory domain updated:
[    8.401387] cfg80211:   (start_freq - end_freq @ bandwidth), 
(max_antenna_gain, max_eirp)
[    8.401389] cfg80211:   (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 
mBi, 2000 mBm)
[    8.401391] cfg80211:   (2457000 KHz - 2482000 KHz @ 40000 KHz), (300 
mBi, 2000 mBm)
[    8.401394] cfg80211:   (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 
mBi, 2000 mBm)
[    8.401396] cfg80211:   (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 
mBi, 2000 mBm)
[    8.401398] cfg80211:   (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 
mBi, 2000 mBm)
[    8.495233] iwlwifi 0000:03:00.0: firmware: agent loaded 
iwlwifi-5000-5.ucode into memory
[    8.495497] iwlwifi 0000:03:00.0: loaded firmware version 8.83.5.1 
build 33692 op_mode iwldvm
[    8.542212] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEBUG disabled
[    8.542216] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEBUGFS disabled
[    8.542218] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEVICE_TRACING disabled
[    8.542221] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEVICE_TESTMODE disabled
[    8.542223] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_P2P enabled
[    8.542226] iwlwifi 0000:03:00.0: Detected Intel(R) WiFi Link 5100 
AGN, REV=0x54
[    8.542255] iwlwifi 0000:03:00.0: L1 Disabled; Enabling L0S
[    8.583031] ieee80211 phy0: Selected rate control algorithm 'iwl-agn-rs'
[   21.923727] iwlwifi 0000:03:00.0: L1 Disabled; Enabling L0S
[   21.924214] iwlwifi 0000:03:00.0: Radio type=0x1-0x2-0x0
[   22.110997] iwlwifi 0000:03:00.0: L1 Disabled; Enabling L0S
[   22.111379] iwlwifi 0000:03:00.0: Radio type=0x1-0x2-0x0
[   22.231955] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[   28.493852] wlan0: authenticate with 10:bf:48:3c:df:b0
[   28.498156] wlan0: send auth to 10:bf:48:3c:df:b0 (try 1/3)
[   28.549658] wlan0: authenticated
[   28.552147] wlan0: associate with 10:bf:48:3c:df:b0 (try 1/3)
[   28.552973] wlan0: RX AssocResp from 10:bf:48:3c:df:b0 (capab=0x11 
status=0 aid=1)
[   28.555965] wlan0: associated
[   28.556052] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[   28.556186] cfg80211: Calling CRDA for country: GB
[   28.566480] cfg80211: Regulatory domain changed to country: GB
[   28.566490] cfg80211:   (start_freq - end_freq @ bandwidth), 
(max_antenna_gain, max_eirp)
[   28.566496] cfg80211:   (2402000 KHz - 2482000 KHz @ 40000 KHz), 
(N/A, 2000 mBm)
[   28.566503] cfg80211:   (5170000 KHz - 5250000 KHz @ 40000 KHz), 
(N/A, 2000 mBm)
[   28.566508] cfg80211:   (5250000 KHz - 5330000 KHz @ 40000 KHz), 
(N/A, 2000 mBm)
[   28.566514] cfg80211:   (5490000 KHz - 5710000 KHz @ 40000 KHz), 
(N/A, 2700 mBm)
[   28.566520] cfg80211:   (57240000 KHz - 65880000 KHz @ 2160000 KHz), 
(N/A, 4000 mBm)

| find /etc -iname *"iwl*" To see whether there are any modprobe 
parameters that disable some things.
| If that doesn't help, you'll probably have to look for support: 
http://wireless.kernel.org/en/users/Support

paul@cygnus:~$ sudo find /etc  find /etc -iname *"iwl*"
[sudo] password for paul:
find: `find': No such file or directory

Many thanks for looking at this - my knowledge of wifi is woefully 
inadequate for troubleshooting this lot...

Cheers.

Paul.