Extremely unstable wireless connection

Tiigon · 2012-01-24 13:28:34

Since Saturday my connection just stops working every 15-30 minutes. Disconnecting and reconnecting solves the problem, but I'm sure there's a better option than netcfg -r'ing all the time.

There was a kernel update on Friday (3.1.9 -> 3.2.1), so I suspect that could be the problem. Any ideas?

EDIT: I noticed there was a new kernel update available, the connection seems to work for now... It worked for over 2 hours yesterday before acting up, though, so I'm not sure if the problem's actually solved yet.

EDIT2: Kernel update didn't help

Last edited by Tiigon (2012-01-24 14:59:09)

Tiigon · 2012-01-27 18:19:09

Bumping, I still need help...

meph · 2012-01-28 06:15:23

Need more input.

For how long it doesn't work (i.e. what packages were updated just before you noticed any problems). You can check that in /var/log/pacman.log.

What kind of wireless card are you using? What kind of interface does it use (usb, pci)? Relevant part of lspci -v will do. Could check online whether you're the only one having that kind of trouble on this particular piece of hardware. Quite possible with some more exotic hw, unlikely on common wifi cards.

Does this happen on only one AP or more? If it's just your home wifi or something similar, then I suggest you also try elsewhere (or a different AP at home) to check it's not a problem in the AP itself. Also it's good to check that your wifi network doesn't just interfere with someone else's, i.e. check what networks are around you and what channel they're running on, and try to fiddle with your own AP settings. If you have an android phone, then you can get a tool called Wifi Analyzer - it shows detectable wifi networks around you, their channels, and puts everything into a well arranged graph. I was amazed when I saw how many AP's there are in crowded areas This problem is actually quite common.

Tiigon · 2012-01-28 14:45:25

Thanks for the reply

There were a lot of updates when it stopped working properly, but here are the ones that look like they could have caused it (there were around 50 updates - I can post the whole list, but I don't think libreoffice or something like that could break anything):

[2012-01-20 21:45] upgraded inetutils (1.9-1 -> 1.9.1-1)
[2012-01-20 21:46] upgraded linux (3.1.9-1 -> 3.2.1-1)
[2012-01-20 21:46] upgraded linux-headers (3.1.9-1 -> 3.2.1-1)

Here's what lspci -v says:

04:01.0 Network controller: Ralink corp. RT2800 802.11n PCI
	Subsystem: ASUSTeK Computer Inc. Device 130f
	Flags: bus master, slow devsel, latency 64, IRQ 16
	Memory at febf0000 (32-bit, non-prefetchable) [size=64K]
	Capabilities: [40] Power Management version 3
	Kernel driver in use: rt2800pci

I've had this computer for almost 2 years and I haven't changed the hardware once, so I don't think the adapter is the problem - unless it's starting to break.

This computer is a desktop, so I really can't move it around to try any other AP... however, every computer in my home is connected to the same AP and they all work properly. My Android phone also works just fine in the same spot where my computer is, so I'm quite sure that the AP isn't the problem.

As I expected, Wifi Analyzer didn't tell very much. I think I can safely say that the networks don't interfere with each other.

There was another kernel update yesterday, I hope it fixes the problem.

meph · 2012-01-28 15:51:35

No problems We're at the beginning though, and wifi problems in my experience are never easy to fix... let's see what we've got

No, whole list really isn't needed. I wouldn't see inetutils as a source of your problems either, so if there isn't more network related packages, then we're left with the kernel. If that's an option, you might consider downgrading to 3.1.9 just to confirm, because if the problem really is in the driver, then there's not much you can do.

Where the hell do you live man, I wish my wifi map looked like yours Anyway, not a case of a faulty AP then, was just looking for a simple solution. Everything indeed points to a hardware problem in your PC, but I don't think the wifi card is dying... these things tend to either work well or not at all.

I asked uncle Google about your kernel driver, and quite a lot of threads over various sites popped up, reporting problems with stability, albeit all of them are a bit older (2011). However, a minor driver alteration might have just brought the problem back, who knows..... One thing I was able to find was that blacklisting the following modules was advised by asus to improve stability: rt2800lib, rt2860sta, rt2800usb, rt2x00lib, rt2x00usb. You might try the same, it's not like you have something to lose.

Summary: I'd start with blacklisting those modules, maybe it's a quick workaround (a long shot, but worth a try). If that doesn't help, try downgrading kernel if you can. And if that doesn't help and your wifi is still unstable on older kernel, then we'll know we have to start looking elsewhere

Tiigon · 2012-01-28 16:45:04

I blacklisted the modules, hopefully it works now. If it doesn't, I'll try downgrading the kernel. How should I do it so that it doesn't destroy the whole system?

EDIT: Still crashes

Last edited by Tiigon (2012-01-28 17:09:44)

meph · 2012-01-28 17:17:12

Well let's hope that will help in the first place Also, just read your comment about new kernel yesterday, you might want to give it a spin as well before downgrading. Maybe the issue, whatever it was, got fixed, and downgrading isn't a permanent solution. It's just more like a diagnostic step.

Anyway, in case you want to downgrade:
(please keep in mind that I'm not at a linux box right now, so you need to check all paths and syntaxes, as I can't verify them myself)

As long as you didn't clear your cache recently, this will give you a list of kernels you can downgrade to:

cd /var/cache/pacman/pkg
ls | grep linux

To install the kernel (just change the file name to whatever's appropriate, if it's not correct):

sudo pacman -U linux-3.1.9-1-x86_64.pkg.tar.gz

If everything goes well, you should see the usual output. Chances are everything will work seamlessly, as you'll only be downgrading to a recent kernel. Still, there's a possibility that pacman will report some package conflicts and refuse to downgrade, in which case you can paste the output here and we'll go through it and see if it's safe to make any further steps.

edit: just read your edit have you updated to the newest kernel? if so and it still crashes, then you might want to try the downgrade. I'll be here in about 2 hours, so will check up on this thread

Last edited by meph (2012-01-28 17:18:37)

Tiigon · 2012-01-28 17:25:25

Yes, I'm using the newest kernel right now, and it still crashes with it

And there seems to be a conflict with the old kernel version:

sudo pacman -U linux-3.1.9-1-i686.pkg.tar.xz 
Password: 
loading packages...
warning: downgrading package linux (3.2.2-1 => 3.1.9-1)
resolving dependencies...
looking for inter-conflicts...
error: failed to prepare transaction (could not satisfy dependencies)
:: nvidia: requires linux>=3.2

meph · 2012-01-28 17:49:01

Just nvidia? That has to be rebuilt every time you change kernel if I remember correctly, right? Can you uninstall it and swap to nouveau just for now? There's a guide on Nouveau wiki, including how to remove nvidia driver safely. Obviously you can reinstall the proprietary driver anytime, even after you downgrade the kernel, it's just that it will give you all sorts of problems while tampering with kernel. It's easier to go with open source right now.

Thinking about it, using --force flag while downgrading could work as well, and reinstalling proprietary driver right after. Though I'm not 100% sure about that, you could end up without X until you reinstall the nvidia driver, so at your own risk.

edit: again I want to point out that the above applies only if nvidia is the only conflicting package. Be especially careful with the pacman --force flag, if there's other packages besides nvidia and you do this, you might end up with a broken system.

Last edited by meph (2012-01-28 17:51:37)

Tiigon · 2012-01-28 18:25:45

Okay, so I switched to nouveau and downgraded the kernel... let's see if it works now

E: 2 hours up, no problems so far. Though it worked for 5 hours one day before crashing...

Last edited by Tiigon (2012-01-28 20:24:33)

meph · 2012-01-28 21:26:35

Indeed, too early to tell I guess, but this whole thing must have been caused by something, and kernel was the most likely suspect. Anyway, when you're sure that this did or did not help, we can go over what's the next step

Tiigon · 2012-01-28 22:54:09

Four and half hours and still working. I'm almost sure that it's working now.

So, what's the next step?

meph · 2012-01-29 08:32:19

Well, there's only so much you can do on your own. Still, there are some things for you to consider.

First, we still don't know if it's a bug that only affects you. It may be more widespread, but I still wasn't able to find anyone reporting similar trouble as you have. It may be caused by the fact that your wifi card isn't that common - it should be supported by the kernel, but the fewer people use a device, the longer it may take until a bug gets recognized and fixed. It still may be caused by something in your system, but I'm out of ideas on how to figure that one out. And since it's a kernel we're talking about, I'm of the opinion that the kernel developers should be made aware of the issue. Here are some guidelines on how to report kernel bugs, but it would be appropriate if someone more accustomed to this process could step in now and give more information on how to proceed. I never had to do something like that myself, so what I'm saying is just what I could find out by googling and directly on kernel.org.

And second, reporting a bug won't fix your immediate problem. Even if you report it, we don't know if it ever gets any serious attention, and even if it does, when it's going to get fixed. Staying on outdated kernel can hardly be called a solution either. So, these are the only options I think you have, besides reporting a bug, which you should do either way:

- keep using older kernel and watch changelogs and your bug report mailing list for any development

- be ok with having to reconnect every now and then while using fully updated system, and again keep watching the situation. You may consider using tools like networkmanager or wicd, which should be able to reconnect you once you lose connection

- since you're using a desktop PC (which I assume you don't move around), consider using ethernet connection for now if that's an option

- get a new wifi card. Simplest solution available, if working wifi is your only option and you can spare the cash, they aren't expensive nowadays anyway. Obviously not a very elegant solution, but it will work for sure

Sorry I couldn't help any more. Again, someone please step in if you have any more ideas.

Tiigon · 2012-01-29 13:03:25

Many thanks for help anyway, at least I now know what the problem is.

I think I'll buy a new wireless card, sounds like the easiest option to me.

meph · 2012-01-29 15:27:50

Tiigon wrote:

Many thanks for help anyway, at least I now know what the problem is.
I think I'll buy a new wireless card, sounds like the easiest option to me.

You're welcome, glad I could do at least that much.

And yep, that's probably what I would do as well.

flyman · 2012-03-17 06:41:33

Hi,

I also had a very unstable wifi connection from about the same time this thread started. I'm not sure how related our problems are because downgrading the kernel didn't help me.

Last night I did a sys upgrade and my wifi has been running without problems since then. Maybe you can try an update again and see if it fixes it.

Arch Linux

#1 2012-01-24 13:28:34

Extremely unstable wireless connection

#2 2012-01-27 18:19:09

Re: Extremely unstable wireless connection

#3 2012-01-28 06:15:23

Re: Extremely unstable wireless connection

#4 2012-01-28 14:45:25

Re: Extremely unstable wireless connection

#5 2012-01-28 15:51:35

Re: Extremely unstable wireless connection

#6 2012-01-28 16:45:04

Re: Extremely unstable wireless connection

#7 2012-01-28 17:17:12

Re: Extremely unstable wireless connection

#8 2012-01-28 17:25:25

Re: Extremely unstable wireless connection

#9 2012-01-28 17:49:01

Re: Extremely unstable wireless connection

#10 2012-01-28 18:25:45

Re: Extremely unstable wireless connection

#11 2012-01-28 21:26:35

Re: Extremely unstable wireless connection

#12 2012-01-28 22:54:09

Re: Extremely unstable wireless connection

#13 2012-01-29 08:32:19

Re: Extremely unstable wireless connection

#14 2012-01-29 13:03:25

Re: Extremely unstable wireless connection

#15 2012-01-29 15:27:50

Re: Extremely unstable wireless connection

#16 2012-03-17 06:41:33

Re: Extremely unstable wireless connection

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