View Full Version : Wireless becomes disabled when on battery power
Jul 30th 2011, 07:57 PM
I have Kubuntu 11.04 amd 64 installed with Broadcom STA wireless driver. When my HP Pavillion dv9925nr laptop is plugged into the AC adapter the wireless works fine. But if I'm running on battery power for even a short time the wireless disconnects and becomes disabled. Even after plugging it back in I cannot enable the wireless without rebooting with the AC adapter plugged in. I'm not talking about a low battery situation, normally when I notice the wireless is no longer available the battery is still in the high 90s.
Jul 30th 2011, 08:52 PM
Is it maybe a BIOS setting or an option in the Power Management?
Jul 30th 2011, 09:34 PM
I do not see anything in the BIOS settings or Kubuntu Power Manager that address this issue. Is there somewhere else I might look?
Jul 31st 2011, 08:05 PM
I've tried creating new power management profiles to use when the AC is unplugged to no avail. Experimenting with various settings. All the settings I try result in loosing wifi after a period of time. Then the only way I can get it back is plug the AC back in and reboot.
I've been searching all over for any mention of a problem similar to mine and a possible fix. I found an article here: Disabling wireless power management in Ubuntu (http://uselessuseofcat.com/?p=67) that seems to be addressing my problem. Since I am rather new to Kubuntu and the article is actually written for Ubuntu 10.10, I was wondering if someone more familiar with Kubuntu 11.04 could have a look at it and see if the solution detailed in the article might help my situation.
Jul 31st 2011, 10:17 PM
any output to dmesg when this occurs?
Jul 31st 2011, 11:16 PM
Sorry, I don't know. What do I need to do to find out?
Aug 1st 2011, 12:06 AM
start up, open a terminal, type "dmesg", wait for the wireless to die, type "dmesg" again and post any new lines.
Aug 1st 2011, 01:06 PM
Well, I've been sitting here poking around the internet, reading the forum and many other article for a couple of hours and the wireless hasn't disabled itself yet. Every other time I have tried to use this laptop on battery only the wireless would be disabled within a half hour to 45 minutes. But not today. Looks like I'm going to have to try this again later.
Aug 1st 2011, 02:47 PM
It's possible being on the battery isn't the problem. For example, I just had a laptop repaired because everytime I moved it, it would lock up. I noticed eventually that the wireless light would go out when this happened. It turned out to be the wireless card was loose or the connector was bad - it was under warranty so they replaced the mobo and wifi card.
Aug 1st 2011, 05:49 PM
Okay, I did try it again and I tried to pay very close attention to everything as it happened (or didn't happen, as the case may be). I restarted the laptop while it was unplugged. A soon as it was finished booting up I opened the Konsole and typed dmesg. A whole lot of stuff printed to the Konsole. I left it up while I went about poking around the internet. After about 30 minutes I was no longer able to get web pages to load. But if I looked at the connection information in the lower right corner of the desktop it appeared that the wireless was still connected. I waited a bit longer. It did appear that somethings on the desktop were locked up but not everything. Things on the lower taskbar stopped responding to clicks. But after a minute or two everything that I had clicked suddenly jumped to life. Eventually the wireless information showed that it was no longer connected. At that point I went back to the still opened Konsole and typed dmesg in again. The window jumped a bit but no new information seemed to be added. Since I wasn't certain what to post to you I copied and pasted the entire Konsole information into Kate and saved the file. I then plugged the power cord in and restarted. Please let me know if you want me to post the contents of the txt file.
I understand you're suggesting there may be some physical problem with the laptop unrelated to the power management/wireless. This is of course a possibility. I have had the laptop for a couple years and until I recently replaced it with Kubuntu, it was running Windows 7 (that I had upgraded from Vista). There were no problems with wireless or power management before under those operating systems. While trying to sort out this problem the laptop has been sitting on my desk and I have not moved it about. But after reading your most resent post I picked it up and shook it :) while it was plugged in, just to sort of rule out the possibility of something being loose. It didn't suffer any lockups or wireless problems after the shake. In case it's relevant the battery is new.
Aug 1st 2011, 09:56 PM
I have a similar problem with my laptop, although I do not lose my wifi connection when on battery power, it does drop considerably from approx 27mbs/s to 7mbs/s, often with the appearance that my connection is down as a page takes forever to load if at all.
When this happens I have to run a script to disable power management while running on battery power.
I did a post regarding this issue, which may or may not be of some use, assuming the problem you are having is in anyway related. Can't recall the title of the post at present, so I'd have to search for it.
Aug 2nd 2011, 01:42 PM
Just a hunch - are you using KDE Network Manager? I am having a similar problem on one of my laptops and I'm pretty sure it's networkmanagers fault. I might have a chance to change over to WICD todya, I'll post back if I'm right.
Aug 2nd 2011, 04:04 PM
Yes, I am using KDE Network Manager.
Aug 3rd 2011, 02:07 PM
This is what happened today....
I started up my laptop while the power cord was plugged in, then I unplugged it after everything was finished starting. I poked around the Internet for about an hour and 15 minutes and at that time web pages stopped loading. The information in the lower right corner of the desktop indicated that the wireless was still connected and enabled. At this point I experienced a momentary desktop freeze up. I plugged the power cord back in, the desktop recovered. Web pages continued not to load. Instead of reboot at this point I decided to give it a little time to see if it would sort itself out. Everything remained the same after 20 minutes. I then decided to go off and do something else for a while and put the laptop into sleep mode. When I returned and woke up the laptop the network information in the lower right corner of the desktop said, "wireless is disabled by hardware." I rebooted. When everything came back up the network information in the lower right corner of the desktop said, "wireless is disabled by software." I was able to click the unchecked "enable" box and the wireless started up right away.
I can of course use the laptop for hours on end with no wireless problems when the power cord is plugged in the entire time.
Aug 3rd 2011, 05:32 PM
Are you prepared to remove Knetwork Manager and try WCID instead? I was having intermittent problems with my wifi when I first installed kubuntu, haven't had any problems with WCID except for a reduction of speed on battery power but that is the power management and not the network manager.
Aug 3rd 2011, 11:27 PM
Okay, I decided it was time to give WICD a try. I have followed the details in this post by Teunis http://kubuntuforums.net/forums/index.php?topic=3117767.msg269436#msg269436 very closely. I made sure that I have gotten rid of KDE Network Manager (knm-runtime and network-manager-kde) stuff and installed WICD including wicd-kde, wicd-deamon, python-wicd and wicd metapackage. I rebooted. WICD started up and appeared in the panel. My network was detected without any problem. However, after spending some time trying to connect it declares that my pass-key is incorrect. I've tried a number of times with the same result. This is of course the pass-key that is working to wirelessly connect a number of devices to my router without any problem. And it worked with the KDE Network Manager. What am I missing here?
EDIT: I did some more digging around in other threads and found that some more remaining snippets of the network-manager were probably the problem. I thought I had gotten everything. I purged them, restarted and WICD connected automatically. So, the wireless is good now.
Now I just have to see if this is going to help when the laptop power cord is disconnected. I'll fool with that tomorrow.
Aug 4th 2011, 11:26 AM
I've been on the laptop using battery power while browsing around the Internet for about 2 1/2 hours. I've even watched a couple YouTube videos. I've had no wireless slow downs or desktop lockups. So, it seems that switching to WICD has done something good. I think the combination of changing Power Manager settings and installing WICD may have cured my problem. But I need to test it out over the next week or so to be sure. I'll post if any problems show up.
Thanks for all the guidance.
Aug 4th 2011, 01:23 PM
In your honor ;D I also changed to WICD one of my laptops. All my mysterious networking problems went away.
I saw the lead developer of KDE Network Manager post on a blog (in response to a review of Kubuntu that included a comment that his program didn't work well) that as far as he knew, there wasn't anything wrong with it. Talk about clueless. With that sort of engineering blindness at the helm, I doubt KNetworkManager will ever work. Thank goodness it's linux and we can install whatever we want!
Aug 4th 2011, 10:55 PM
I've been using WICD for quite some time and originally it was out of need, knetworkmanager just wouldn't work for me with WPA security.
But since the present 11.04 release I've on the same hardware finally and without trouble been able to use the knm network management.
And although it is prettier than WICD I still feel WICD gives me better control over the various network settings.
Aug 5th 2011, 07:43 AM
Thank goodness it's linux and we can install whatever we want!
Absolutely! Isn't that why we're all here? ;D
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