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Ticket #447 (new defect)

Opened 12 years ago

Last modified 10 years ago

Power management commands using iwconfig not working

Reported by: Assigned to:
Priority: minor Milestone: version 2.0.0 - far away
Component: madwifi: driver Version: trunk
Keywords: Cc:
Patch is attached: 0 Pending:

Description (Last modified by mrenzmann)

I try to ask the community if this was normal or not and got no response. Sorry if my request does not belong here but thanks for your help

  • Cards are Linksys WPC55AG
  • Distrib is ubuntu
  • Madwifi is the latest from svn
client:~$ sudo iwconfig ath0 power on
Error for wireless request "Set Power Management" (8B2C) :
    SET failed on device ath0 ; Operation not supported.
client:~$ iwlist --version
iwlist    Wireless-Tools version 28
          Compatible with Wireless Extension v11 to v19.

Kernel    Currently compiled with Wireless Extension v19.

ath0      Recommend Wireless Extension v13 or later,
          Currently compiled with Wireless Extension v19.

Change History

03/06/06 21:40:10 changed by mrenzmann

  • priority changed from major to minor.
  • owner changed.
  • component changed from madwifi: tools to madwifi: driver.
  • description changed.
  • milestone set to version 2.0.0 - far away.

05/18/06 15:43:02 changed by

I've the same problem with a different configuration... distrib : Fedora Core 5 kernel 2.6.16 card : DLink DWL-AG650 madifi is the latest downloadable...

i don't understand why it's not working !!! :-( Thanks

(follow-up: ↓ 10 ) 06/01/06 23:59:04 changed by

This feature is pretty important to us here at Pepper. We're looking at an Athereos-based WiFi card for our next generation Pepper Pad, a handheld Linux-based Multimedia Player/Internet device. Think anti-Origami/UMPC.

Low-power mode == longer battery life.

I've gone over the latest snapshot code (r1611) and have found that although the upper ieee80211 layer has support for the power ioctls ( SIOCGIWPOWER/SIOCSIWPOWER ), the lower layers of MADWiFi do not. The ieee80211_ioctl_siwpower() function checks to see if the IEEE80211_C_PGMT capability is set in ieee8011com.ic_caps, if it's not set, then the errno EOPNOTSUPP is returned.

Also it appears that there's not much support for low-power-mode exposed by the HAL ( v0.9.17.0 ). The only non-transmit related power functions exported are the get/setpower methods. The setpower function takes a parameter of type HAL_POWER_MODE which can be:

typedef enum {
        HAL_PM_AWAKE            = 0,
        HAL_PM_FULL_SLEEP       = 1,
        HAL_PM_NETWORK_SLEEP    = 2,
        HAL_PM_UNDEFINED        = 3

HAL_PM_AWAKE is used in two places, but neither of the other modes appear to ever be set. The function ath_stop() has a call to setpower using the mode HAL_PM_FULL_SLEEP, however this code has been removed with an #if 0 conditional.

Besides the fact that these modes may not be used reliably, there also doesn't appear to be anyway to set the sleep period, timeout and multicast flags via the HAL.

06/02/06 00:00:32 changed by

I also would like to add that if there's some way to ask Atheros to expose more of the power-save mode functions in the HAL, I'd be willing to help implement the code in the lower layers of MADWiFi.

06/16/06 08:21:08 changed by

I was just considering switching from Windows to Linux on my Thinkpad X60s.

There's some irritating bugs in the wifi power management on windows, and part of the reason why I wanted to switch to Linux was hopes of having better power management.

However, it appears that there's no power management at all in this MadWifi atheros drivers.

I'm willing to work on whatever code needs to be added to get this working as well.

05/24/07 20:26:06 changed by anonymous

I hope iwconfig ath0 power 1


07/27/07 15:46:10 changed by

Is is posssible to enable power save mode using the function which are diable/commented in present code by uncommenting and using them.

09/05/07 21:37:00 changed by

hi...i'm also facing the same problem with the power management command...can anyone help me by telling me how to solve it..i'm doing a research in power saving mechanisms in IEEE802.11 wireless LAN..for my project,i'm using a D-link wireless card, DWL-G650 with a D-link router..i tried to create an AP and a station by using this:-

wlanconfig ath create wlandev wifi0 wlanmode ap -ath0 wlanconfig ath create wlandev wifi0 wlanmode sta nosbeacon -ath1

after creating n configure both of seem like the ap is useless as the sta can directly connect to the internet without accessing to the ap..can anyone help me with it.furthermore,i really need help in configuring the power saving mode as i'm still new in madwifi..

hope to receive an email soon..really urgent!!!thank you

10/18/07 08:22:15 changed by ANONYM

I have the same problem. No power management is present on madwifi driver.

(in reply to: ↑ 3 ; follow-up: ↓ 11 ) 02/23/08 20:01:59 changed by pthagonal

I also strongly disagree with the classification of this issue as "minor".

I believe that power management and the ability to save energy is _very_ important. What's "minor" about wasting?! Just to give you an idea: powertop indicates that more than half (!) of the causes for wakeups, which result in increased power consumption, are due to wifi0 interrupts. More specifically, the top causes for wakeups result in about 21.5 wakeups-per-second, and 14.5 of those are due to wifi.

I suggest supporting the iwconfig ath0 power on call with version 1.0, at the latest. Any chances? ;-)

(in reply to: ↑ 10 ) 02/24/08 08:50:35 changed by mrenzmann

Replying to pthagonal:

I suggest supporting the iwconfig ath0 power on call with version 1.0, at the latest. Any chances? ;-)

Very little. MadWifi has been declared legacy for a reason. ath5k is the future, and as far as I can tell, proper power saving support is much more likely to appear in ath5k once the more pressing issues have been fixed there.