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8devices / carambola

Carambola - RT305x/SoC based PCB
http://openwrt.org/
GNU General Public License v2.0
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Strange iwlist behavior #10

Closed Lukse closed 11 years ago

Lukse commented 11 years ago

It is like Russian roulette. You never know what to expect.

Here is log of several attempts to run [iwlist wlan0 scan] command.

root@OpenWrt:/# iwlist wlan0 scan wlan0 Interface doesn't support scanning : Device or resource busy

root@OpenWrt:/# iwlist wlan0 scan wlan0 Interface doesn't support scanning : Device or resource busy

root@OpenWrt:/# iwlist wlan0 scan wlan0 Scan completed : Cell 01 - Address: 36:5A:05:E7:BC:A5 Channel:1 Frequency:2.412 GHz (Channel 1) Quality=42/70 Signal level=-68 dBm
Encryption key:on ESSID:"iPhone" Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s 36 Mb/s; 48 Mb/s; 54 Mb/s Mode:Master Extra:tsf=000000000014503c Extra: Last beacon: 1760ms ago IE: Unknown: 00066950686F6E65 IE: Unknown: 01088C129824B048606C IE: Unknown: 030101 IE: Unknown: 2A0100 IE: Unknown: 2F0100 IE: IEEE 802.11i/WPA2 Version 1 Group Cipher : CCMP Pairwise Ciphers (1) : CCMP Authentication Suites (1) : PSK IE: Unknown: DD0A0017F206010103010000 IE: Unknown: DD0D0017F206020106145A05E7BCA4 IE: Unknown: DD09001018020000450000 IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00

valinskas commented 11 years ago

Messages below indicate that you have attempted to request scan operation while it is already in progress. So this is not a problem I think it is expected.

root@OpenWrt:/# iwlist wlan0 scan
wlan0 Interface doesn't support scanning : Device or resource busy

root@OpenWrt:/# iwlist wlan0 scan
wlan0 Interface doesn't support scanning : Device or resource busy
valinskas commented 11 years ago 
`--> sudo iw dev wlan0 scan trigger <-- initiates scan
`--> sudo iw dev wlan0 scan trigger <-- further attempts to initiate scan will fail with -EBUSY
command failed: Device or resource busy (-16)
`--> sudo iw dev wlan0 scan trigger
command failed: Device or resource busy (-16)
`--> sudo iw dev wlan0 scan trigger
command failed: Device or resource busy (-16)
`--> sudo iw dev wlan0 scan trigger
command failed: Device or resource busy (-16)
`--> sudo iw dev wlan0 scan trigger
command failed: Device or resource busy (-16)
`--> sudo iw dev wlan0 scan trigger
command failed: Device or resource busy (-16)
`--> sudo iw dev wlan0 scan trigger
command failed: Device or resource busy (-16)
`--> sudo iw dev wlan0 scan trigger
command failed: Device or resource busy (-16)

# some time later
`--> sudo iw dev wlan0 scan trigger <-- initiates scan ok, no error.

This was tested on my laptop Ubuntu/12.04 LTS