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Ticket #1322 (new defect)

Opened 15 years ago

Last modified 14 years ago

unable to connect, random connection loss, system freeze

Reported by: drebon@crans.org Assigned to:
Priority: major Milestone:
Component: madwifi: other Version: v0.9.3
Keywords: connection loss, association fail, freeze Cc:
Patch is attached: 0 Pending:

Description

I'm using madwifi 0.9.3 under Ubuntu Feisty Fawn amd64 (kernel 2.6.20-15-generic), with an Atheros AR5005G 802.11abg NIC (rev 01) card.

Very often I'm unable to conect even thought the signal strength is good. It seems that I can'nt change the channel or the frequence used by the card (iwconfig ath0 chan X or freq X just do nothing most of the time)

iwlist ath0 scan works prety well, creating a monitor mode VAP seems also quite ok most of the time.

So very often I have great difficulty connecting to a wireless network (it seems that the card is'nt event trying to associate with the AP), and when I'am connected, I often experience connection loss, but luckily most of the time after a connection loss it is easier to connect than the first connection after boot up.

The problems seems to be more often with networks on channel 3 or 10, but I'm not sure this is fully reliable.

I found a workaround for the connection difficulty which is to boot on windows, let windows connect to the targeted wireless network, wait a little, then reboot under linux, and try to connect to the same network windows did connect to. This works well 90% of the time.

When experiencing serious connection issues, it is not rare that cpu utilisation raise 100% (even thought I have a dual core cpu, the both cores are used to 100%) and have no other choice than to reboot with "alt+impr+e/s/B" sequence.

the freeze issue occurs more often after a connection loss which result in a difficult reconnection (so not the most frequent case) than with boot up connection difficulty.

Change History

(in reply to: ↑ description ; follow-up: ↓ 2 ) 05/21/07 06:54:02 changed by mrenzmann

Replying to drebon@crans.org:

Very often I'm unable to conect even thought the signal strength is good.

Not enough information provided. Are you trying to connect to your own AP or to a foreign? What is the signal strength exactly at that time? Does the AP use any encryption, and if so, did you double-check that the encryption credentials are correct?

It seems that I can'nt change the channel or the frequence used by the card (iwconfig ath0 chan X or freq X just do nothing most of the time)

If you do that while your card is associated to an AP, this is expected behaviour. Otherwise you have to give more information.

When experiencing serious connection issues, it is not rare that cpu utilisation raise 100% (even thought I have a dual core cpu, the both cores are used to 100%) and have no other choice than to reboot with "alt+impr+e/s/B" sequence.

Did you try to find out about the cause of the high load? Is it related to MadWifi, or is it just something else that your distro fires up when it notices you are connected to an AP?

the freeze issue occurs more often after a connection loss which result in a difficult reconnection (so not the most frequent case) than with boot up connection difficulty.

Check DevDocs/KernelOops and see if you can provide a dump of an eventually occuring oops.

(in reply to: ↑ 1 ; follow-up: ↓ 3 ) 06/17/07 22:13:29 changed by anonymous

Replying to mrenzmann:

Replying to drebon@crans.org:

Very often I'm unable to conect even thought the signal strength is good.

Not enough information provided. Are you trying to connect to your own AP or to a foreign? What is the signal strength exactly at that time? Does the AP use any encryption, and if so, did you double-check that the encryption credentials are correct?

I'm trying to connect to two acces points :

  • one is an acces point in my house, the signal strength is pretty strong with a link quality allways above 35/94 (Windows gives me an excellent signal strength)

  • the other is at my university network, pretty good signal strength to

It seems that I can'nt change the channel or the frequence used by the card (iwconfig ath0 chan X or freq X just do nothing most of the time)

If you do that while your card is associated to an AP, this is expected behaviour. Otherwise you have to give more information.

I do this when my card does'nt seems to be able to associate. If I look at what NetworkManager says, it changes the essid as it shall be, but just keep switching the frequency (and seems to rarely use the actual frequence of the AP) and never associates. I try to set the correct frequence, but the command juste seems to be ignored.

When experiencing serious connection issues, it is not rare that cpu utilisation raise 100% (even thought I have a dual core cpu, the both cores are used to 100%) and have no other choice than to reboot with "alt+impr+e/s/B" sequence.

Did you try to find out about the cause of the high load? Is it related to MadWifi, or is it just something else that your distro fires up when it notices you are connected to an AP?

Well I think the freeze is maybe more related to Xorg, but I'm not completly sure right now

Do you know what version of madwifi was shipped in Edgy ? I may try to downgrad to it and see if there is the same difficulties there.

I cannot really compare with when I was under Edgy, because I was in France and now I'm in Danemark, so I do not have the same AP's nor network configuration anymore.

(in reply to: ↑ 2 ) 06/27/07 11:41:18 changed by mrenzmann

Replying to anonymous:

I do this when my card does'nt seems to be able to associate. If I look at what NetworkManager says, it changes the essid as it shall be, but just keep switching the frequency (and seems to rarely use the actual frequence of the AP) and never associates. I try to set the correct frequence, but the command juste seems to be ignored.

Do you (or NetworkManager) use something like wpa_supplicant in the background? Anyway, I'm not sure if fixing a STA VAP to a certain channel works at all. IMO it should, and if it really does not this should become subject for a patch.

Do you know what version of madwifi was shipped in Edgy ? I may try to downgrad to it and see if there is the same difficulties there.

No, sorry. I'm no frequent Ubuntu user so far. I have it (the last stable distro, whatever its name was) installed on my notebook, but don't come around to use it frequently.