Unable to set txpower on wifi card

Rick Stevens ricks at nerd.com
Mon Aug 30 18:32:08 UTC 2010


On 08/30/2010 10:41 AM, JD wrote:
>    F13, latest updates.
> wifi card: Sparklan wmir-200N
> http://www.sparklan.com/product.php?func=view&prod_id=43
> Chipset: RT2860/RT2850
>
> The Datasheet says:
>
> Output Power
> 802.11a: 12.5dBm ± 1.5dBm
> 802.11b: 17dBm ± 1.5dBm
> 802.11g: 14dBm ± 1.5dBm
> 802.11an: 14dBm ± 1.5dBm
> 802.11gn: 14dBm ± 1.5dBm
>
> I am running in g mode (54megabits/s)
>
> $ sudo iwconfig wlan0
> wlan0     IEEE 802.11abgn  ESSID:"Deleted"
>             Mode:Managed  Frequency:2.462 GHz  Access Point:
> aa:bb:cc:dd:ee:ff
>             Bit Rate=54 Mb/s   Tx-Power=8 dBm<<<=====
>             Retry  long limit:7   RTS thr:off   Fragment thr:off
>             Encryption key:off
>             Power Management:on
>             Link Quality=70/70  Signal level=58 dBm
>             Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
>             Tx excessive retries:0  Invalid misc:0   Missed beacon:0
>
> I tried to set txpower to 14 per datasheet spec:
>
> $ sudo iwconfig wlan0 txpower 14dBm
> Error for wireless request "Set Tx Power" (8B26) :
>       SET failed on device wlan0 ; Invalid argument.
>
> The drivers that are loaded for this wifi card are:
>
> rt2800pci               7931  0
> rt2800lib              27818  1 rt2800pci
> rt2x00pci               5799  1 rt2800pci
> rt2x00lib              25936  3 rt2800pci,rt2800lib,rt2x00pci
> mac80211              182154  2 rt2x00pci,rt2x00lib
> cfg80211              135626  2 rt2x00lib,mac80211
> eeprom_93cx6            1305  1 rt2800pci
> crc_ccitt               1311  2 rt2800pci,irda
>
> Is this an issue with the wext driver or with the rt2XXXXX drivers?

Try "sudo iwconfig wlan0 txpower 14".  The "dBm" is assumed by the
command.  "man iwconfig" for details.
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- Rick Stevens, Systems Engineer, C2 Hosting          ricks at nerd.com -
- AIM/Skype: therps2        ICQ: 22643734            Yahoo: origrps2 -
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-           Vegetarian:  Old Indian word for "lousy hunter"          -
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