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Error #292

tancat

Wireless card is configured with SHORT-GI-20 despite not supporting it

Afegit per Roger Pueyo Centelles fa casi 10 anys. Actualitzat fa casi 10 anys.

Estat:
Tancat
Prioritat:
Alta
Categoria:
Init scripts
Versió prevista:
-
Inici:
12-06-2014
Data de venciment:
% realitzat:

100%

Temps previst:
1:00 h
Temps invertit:

Descripció

Scenario: Alix2 with one mini-PCI DNMA-92 wireless card (802.11abgn AR9220).

iw list gives the following information:

root@qMp-ac50:/# iw list
Wiphy phy0
    Band 1:
        Capabilities: 0x11ce
            HT20/HT40
            SM Power Save disabled
            RX HT40 SGI
            TX STBC
            RX STBC 1-stream
            Max AMSDU length: 3839 bytes
            DSSS/CCK HT40
        Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
        Minimum RX AMPDU time spacing: 8 usec (0x06)
        HT TX/RX MCS rate indexes supported: 0-15
        Frequencies:
            * 2412 MHz [1] (20.0 dBm)
[...]
    Band 2:
        Capabilities: 0x11ce
            HT20/HT40
            SM Power Save disabled
            RX HT40 SGI
            TX STBC
            RX STBC 1-stream
            Max AMSDU length: 3839 bytes
            DSSS/CCK HT40
        Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
        Minimum RX AMPDU time spacing: 8 usec (0x06)
        HT TX/RX MCS rate indexes supported: 0-15
        Frequencies:
            * 5180 MHz [36] (16.0 dBm)
[...]

wifi detect gives the following conifguration:

root@qMp-ac50:/# wifi detect
config wifi-device  radio0
    option type     mac80211
    option channel  11
    option hwmode    11ng
    option path    'pci0000:00/0000:00:0c.0'
    option htmode    HT20
    list ht_capab    SHORT-GI-40
    list ht_capab    TX-STBC
    list ht_capab    RX-STBC1
    list ht_capab    DSSS_CCK-40
    # REMOVE THIS LINE TO ENABLE WIFI:
    option disabled 1

config wifi-iface
    option device   radio0
    option network  lan
    option mode     ap
    option ssid     OpenWrt
    option encryption none

However, the auto-configuration process adds the SHORT-GI-20 capability to the wireless card in /etc/config/wireless:

config wifi-device 'radio0'
        option type 'mac80211'
        option macaddr '90:a4:de:c0:bb:c1'
        option channel '1'
        option country 'SP'
        option hwmode '11ng'
        option htmode 'HT20'
        option txpower '17'
        option noscan '1'
        option distance '5000'
        list ht_capab 'SHORT-GI-20'
        list ht_capab 'SHORT-GI-40'
        list ht_capab 'RX-STBC1'
        list ht_capab 'DSSS_CCK-40'

config wifi-iface 'wlan0'
        option device 'radio0'
        option mode 'adhoc'
        option ssid 'qMp'
        option bssid '02:CA:FF:EE:BA:BE'
        option ifname 'wlan0'
        option network 'mesh_w0'

config wifi-iface 'wlan0ap'
        option device 'radio0'
        option mode 'ap'
        option ssid 'qMp-AP'
        option network 'lan'
        option encryption 'none'
        option ifname 'wlan0ap'

Then, when the wireless is reset with the wifi command, the following error appears:

root@qMp-ac50:/# wifi 
command failed: Device or resource busy (-16)
Configuration file: /var/run/hostapd-phy0.conf
wlan0ap: interface state UNINITIALIZED->COUNTRY_UPDATE
Driver does not support configured HT capability [SHORT-GI-20]
wlan0ap: Unable to setup interface.
hostapd_free_hapd_data: Interface wlan0ap wasn't started
Failed to start hostapd for phy0

and the interface is not brought up.

The configuration script should be reviewed to ensure that only the supported features are enabled.

Actions #1

Actualitzat per Roger Pueyo Centelles fa casi 10 anys

  • Estat ha canviat de Nou a Resolt
  • Assignat a s'ha establert a Roger Pueyo Centelles
  • % realitzat ha canviat de 0 a 100
  • Temps previst s'ha establert a 1:00 h

Commented "list wireless.#QMP_RADIO.ht_capab=SHORT-GI-20" from:

/etc/qmp/templates/wifi/device.mac80211-auto
/etc/qmp/templates/wifi/device.mac80211-na
/etc/qmp/templates/wifi/device.mac80211-ag

Commits:

master: f734aaff9ac41675445c5c5de653474d9e0358fb
testing: 32067e7fdece17b9c9297797cb9505a2b3c02895
kalimotxo: 6c0de0e0279d79e4856a6e2285460f3d93251229

This prevents the driver from enabling the short guard interval in 20 MHz channel width operation. It was enabled by default for all 802.11n radios, but it seems that some cards do not support it. OpenWrt detects it correctly and saves it in /etc/config/wireless, so this file or the same detection procedure could be used.

Actions #2

Actualitzat per Roger Pueyo Centelles fa casi 10 anys

  • Estat ha canviat de Resolt a Tancat
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