10ec:8171 wifi network get disconnected periodically -- Realtek RTL8191SEvA

Thanks for reporting this.

can you please add info about your hardware as well using ifconfig, and reports of the connection attempts using dmesg|grep wlan on the terminal?

The laptop is a HP G32, standard configuration, i3 with 4G ram.

previous ifconfig log contains Chinese text, this one is English

lspci output:

00:00.0 Host bridge: Intel Corporation Core Processor DRAM Controller (rev 02)
00:01.0 PCI bridge: Intel Corporation Core Processor PCI Express x16 Root Port (rev 02)
00:16.0 Communication controller: Intel Corporation 5 Series/3400 Series Chipset HECI Controller (rev 06)
00:1a.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 05)
00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 05)
00:1c.0 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 (rev 05)
00:1c.1 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 2 (rev 05)
00:1d.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 05)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev a5)
00:1f.0 ISA bridge: Intel Corporation Mobile 5 Series Chipset LPC Interface Controller (rev 05)
00:1f.2 SATA controller: Intel Corporation 5 Series/3400 Series Chipset 4 port SATA AHCI Controller (rev 05)
00:1f.3 SMBus: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller (rev 05)
01:00.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI Manhattan [Mobility Radeon HD 5400 Series]
01:00.1 Audio device: Advanced Micro Devices [AMD] nee ATI Cedar HDMI Audio [Radeon HD 5400/6300 Series]
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller (rev 02)
03:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8191SEvA Wireless LAN Controller (rev 10)
ff:00.0 Host bridge: Intel Corporation Core Processor QuickPath Architecture Generic Non-core Registers (rev 05)
ff:00.1 Host bridge: Intel Corporation Core Processor QuickPath Architecture System Address Decoder (rev 05)
ff:02.0 Host bridge: Intel Corporation Core Processor QPI Link 0 (rev 05)
ff:02.1 Host bridge: Intel Corporation Core Processor QPI Physical 0 (rev 05)
ff:02.2 Host bridge: Intel Corporation Core Processor Reserved (rev 05)
ff:02.3 Host bridge: Intel Corporation Core Processor Reserved (rev 05)

I found that the problem is related to the location of my laptop! It might not be a Ubuntu related but (e.g. a hardware/environmental problem?), but, there are still hints that I think it is related to ubuntu:

1) the location difference is only relevant in my home, i.e. if I move the laptop out of this specific room it is ok. There is no problem if the laptop sits in another room, or brought to my office).

2) As I emphasised before, there is no problem with other devices in the same room

3) I plugged in a usb wifi adapter, which is recognized as wlan1, can be used without problem, although its signal level seems low (speed is ok). Info about the new usb wifi adapter (Buffalo) are:

a) dmesg:

[ 19.137557] ADDRCONF(NETDEV_UP): wlan1: link is not ready
[ 19.137952] ADDRCONF(NETDEV_UP): wlan1: link is not ready
[ 22.641581] wlan1: authenticate with 14:e6:e4:3b:d2:1e (try 1)
[ 22.643452] wlan1: authenticated
[ 22.709774] wlan1: associate with 14:e6:e4:3b:d2:1e (try 1)
[ 22.713412] wlan1: RX AssocResp from 14:e6:e4:3b:d2:1e (capab=0x431 status=0 aid=2)
[ 22.713419] wlan1: associated
[ 22.713425] wlan1: No basic rates in AssocResp. Using min supported rate instead.
[ 22.745064] ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
[ 32.965311] wlan1: no IPv6 routers present

b) lsusb:

Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 003: ID 09da:054f A4 Tech Co., Ltd
Bus 002 Device 003: ID 0411:01a2 BUFFALO INC. (formerly MelCo., Inc.) WLI-UC-GNM Wireless LAN Adapter
Bus 002 Device 004: ID 10f1:1a27 Importek

c) syslog - attached.

Does it make any difference if you comment out "dns=dnsmasq" in /etc/NetworkManager/NetworkManager.conf?

... and restart network-manager ...?

Also, does the machine behave differently running another operating system, e.g., an earlier version of Ubuntu?

Results:

1) Good news: by commenting out dnsmasq, it *SEEMS* to work well. Why I say "seems"? Because before that it is also able to connect "sometimes". So I need to test longer, especially see if I can still connect next morning...

2) This problem ONLY happens after install 12.04, it does not happen in 11.10 or earlier (same hardware). Also after this problem happens I suspected its ubuntu problem, and removed 12.04, installed Fedora 16, SAME problem, then I revered back to Ubuntu and did other tests.

3) The most strange issue, even you confirmed it is dnsmasq related, is that it seems related to location of the laptop!

BTW, if it is OK next morning, I will try to uncomment dnsmasq see if the problem reappear or not. I will report back. thanks.

I am sorry that this does NOT solve the problem. It just made the first connection easier. The connection failed after about 0.5~1 hour (which is good, comparing to its MTBF before the tweak), but then it never succeeded to recover. I also tried this morning, and never get connected, until I move the laptop to a "connect-able" location.

If you boot another OS on the same laptop, do you have the same problem?

Hi Thomas,

I tried Fedora 16 on the laptop which had same problem, but I am sorry I can't install windows on this laptop because I don't want to re-partition or move my data.

HI,

I can confirm this type of issue with my Dell vostro 3300, i5 . This has started happening after the 12.04 upgrade. I have windows 7 on my system. I have tested, it does not get disconnected . There is not issue with the wifi as my android device , galaxy s2 , never gets disconnected from the wifi.

 :~dmesg | grep wlan
[77330.387668] wlan0: authenticate with 2c:b0:5d:f1:4b:d0 (try 1)
[77330.587210] wlan0: authenticate with 2c:b0:5d:f1:4b:d0 (try 2)
[77330.786874] wlan0: authenticate with 2c:b0:5d:f1:4b:d0 (try 3)
[77330.986540] wlan0: authentication with 2c:b0:5d:f1:4b:d0 timed out
[77336.794190] wlan0: authenticate with 2c:b0:5d:f1:4b:d0 (try 1)
[77336.795884] wlan0: authenticated
[77336.796091] wlan0: associate with 2c:b0:5d:f1:4b:d0 (try 1)
[77336.799822] wlan0: RX ReassocResp from 2c:b0:5d:f1:4b:d0 (capab=0x411 status=0 aid=16)
[77336.799828] wlan0: associated
[77808.148817] wlan0: authenticate with 2c:b0:5d:f1:4b:d0 (try 1)
[77808.348367] wlan0: authenticate with 2c:b0:5d:f1:4b:d0 (try 2)
[77808.548038] wlan0: authenticate with 2c:b0:5d:f1:4b:d0 (try 3)
[77808.747722] wlan0: authentication with 2c:b0:5d:f1:4b:d0 timed out
[77814.551288] wlan0: direct probe to 2c:b0:5d:f1:4b:d0 (try 1/3)
[77814.749318] wlan0: direct probe to 2c:b0:5d:f1:4b:d0 (try 2/3)
[77814.948987] wlan0: direct probe to 2c:b0:5d:f1:4b:d0 (try 3/3)
[77815.148667] wlan0: direct probe to 2c:b0:5d:f1:4b:d0 timed out
[77820.950655] wlan0: direct probe to 2c:b0:5d:f1:4b:d0 (try 1/3)
[77821.150239] wlan0: direct probe to 2c:b0:5d:f1:4b:d0 (try 2/3)
[77821.349884] wlan0: direct probe to 2c:b0:5d:f1:4b:d0 (try 3/3)
[77821.549553] wlan0: direct probe to 2c:b0:5d:f1:4b:d0 timed out
[77822.505266] ADDRCONF(NETDEV_UP): wlan0: link is not ready
[77827.369192] wlan0: authenticate with 2c:b0:5d:f1:4b:d0 (try 1)
[77827.373596] wlan0: authenticated
[77827.374104] wlan0: associate with 2c:b0:5d:f1:4b:d0 (try 1)
[77827.377960] wlan0: RX ReassocResp from 2c:b0:5d:f1:4b:d0 (capab=0x411 status=0 aid=16)
[77827.377966] wlan0: associated
[77827.380222] ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[77837.745467] wlan0: no IPv6 routers present
[77928.647903] wlan0: authenticate with 2c:b0:5d:f1:4b:d0 (try 1)
[77928.847453] wlan0: authenticate with 2c:b0:5d:f1:4b:d0 (try 2)
[77929.047106] wlan0: authenticate with 2c:b0:5d:f1:4b:d0 (try 3)
[77929.246747] wlan0: authentication with 2c:b0:5d:f1:4b:d0 timed out
[77935.046466] wlan0: direct probe to 2c:b0:5d:f1:4b:d0 (try 1/3)
[77935.244414] wlan0: direct probe to 2c:b0:5d:f1:4b:d0 (try 2/3)
[77935.444074] wlan0: direct probe to 2c:b0:5d:f1:4b:d0 (try 3/3)
[77935.643696] wlan0: direct probe to 2c:b0:5d:f1:4b:d0 timed out
[77941.451369] wlan0: authenticate with 2c:b0:5d:f1:4b:d0 (try 1)
[77941.453060] wlan0: authenticated
[77941.453286] wlan0: associate with 2c:b0:5d:f1:4b:d0 (try 1)
[77941.457127] wlan0: RX ReassocResp from 2c:b0:5d:f1:4b:d0 (capab=0x411 status=0 aid=16)
[77941.457133] wlan0: associated
[78028.047914] wlan0: authenticate with 2c:b0:5d:f1:4b:d0 (try 1)
[78028.247423] wlan0: authenticate with 2c:b0:5d:f1:4b:d0 (try 2)
[78028.447142] wlan0: authenticate with 2c:b0:5d:f1:4b:d0 (try 3)
[78028.646808] wlan0: authentication with ...

I found a problem related to this. I have 2 APs sharing a common SSID, the Ubuntu laptop insist on connecting to the AP downstairs, instead of the AP just 2 meters away! That's why it is so unstable.

NM will roam automatically if there is a network with a higher signal level, once the difference passes a particular point. Perhaps the closest AP is just prone to more interference, and setup on a busy channel?

Regardless, if it's location-related, it's mostly a matter of signal levels and interference, busyness of a particular channel or whatnot; so not an issue with NetworkManager.

I'm willing to give this a bit more testing, just in case there really is something suboptimal that we can fix in NetworkManager or wpasupplicant.

Can you please run:

sudo python /usr/lib/NetworkManager/debug-helper.py --wpa debug --nm debug

Reproduce the issue (without restarting if possible, because then you'll want to run that script again); and attach the full contents of /var/log/syslog?

Thanks!

Please allow me a few days then do this test. I am now trying another trick which seems solved the issue, but I need a few more days to test. What I did is that I setup 2 network connections, with same SSID, but different BSSID, now it can connect to the nearby AP. I will do your test after switching back to my original config this weekend.

Also, signal level difference is physically impossible. Because the farther away AP is on the ground floor, while I am sitting in a room on the 3rd floor, and if I move my laptop to the door of that room it can find AP signal on the first floor, but when I move to the desk, it cannot connect to that AP because of signal level, but it just refused to connect to the nearby AP.

Also please see the attached screenshot. It shows how this stubborn computer insists on connecting to the AP which is at least 7 meters away with 2 floors and a few walls in between. But strangely, before I setup the 10.0.0.1 connection it cannot connect to that AP successfully...

Nothing is looking wrong in /var/log/syslog. What's peculiar though is that the whole scan isn't shown.

Could you run 'sudo iw dev wlan0 scan' and attach the results here?

It seems as though the F4:... AP is the one that gets in scan results, so far. This might be a kernel issue.

Since moving from 10.04 to 12.04 (via a clean install), I'm seeing symptoms similar to what's reported by the original poster. The WiFi connection frequently roams from one AP to another (even though the laptop has not been moved), and ultimately it fails to connect at all.

If I move to a different location in the facility, the problem goes away. Thus, I suspect it's a function of the relative signal quality of the various APs.

When the laptop is booted into Windows 7, in the location (my office) that is most problematic, the WiFi connection is stable.

My adapter is an Intel 5300 with the iwlwifi driver.

I have syslog's and other info if you want it. I can also experiment with alternative kernels and configuration changes.

Hi, while helping someone else with this very same issue I found this post:
http://ubuntuforums.org/showthread.php?t=1834478

Can someone test with realtek's latest driver and confirm if that works? Then it would be a matter of asking for this driver to be available via the hardware drivers tools, but at least a workaround would do it for now.

Direct link to the driver:
http://www.realtek.com/downloads/downloadsView.aspx?Langid=1&PNid=48&PFid=48&Level=5&Conn=4&DownTypeID=3&GetDown=false&Downloads=true#2302

Looks like a driver issue. I sanitized the instructions from several sources, the person I was helping reported apparent initial success with the Realtek driver built+installed manually:

1) Make sure the system is up to date and development tools are installed:
sudo apt-get update && sudo apt-get upgrade -y && sudo apt-get dist-upgrade -y
sudo apt-get install --reinstall build-essential
sudo apt-get install --reinstall linux-headers-generic
sudo apt-get install --reinstall linux-headers-`uname -r`

2) Get the appropriate driver file from realtek.com. Its name will end with .tar.gz. The model you are looking for is RTL8191SE (NOT VA2).

3) Open a terminal, go to the folder where the file was saved:

$ cd Downloads

4) Uncompress the file:
$ tar -xvzf 92ce_se_de_linux_mac80211_0005.1230.2011.tar.gz

5) Change to the directory
$cd rtl_92ce_92se_92de_linux_mac80211_0005.1230.2011

6) Build & install
    1. Change to Super User
       $ sudo -s
    2. Compile driver from the source code , install it to the kernel
       # make && make install
   3. Reboot:
       # reboot

Hi,

Could you please also tell me the procedure to uninstall this driver in case the situation become worse?

The status for me now is that I have explicitely bind my nic to the nearby AP's mac address. It is now pretty much ok, HOWEVER, signal level is still quite bad (at just 2 meters away, the signal strength is around 40% (just estimation from the icon), and speed of download from my NAS is slow.

I can confirm similar problems of dropped connections. It has been working stable for 1 year on Ubuntu 11.10 (Oneiric Ocelot). Upgraded to 12.04.1 and I now have intermittent problems. Network card is RTL8191SEvA and the native driver loaded is rt8192SE. Is there an upstream fix for this ? If I install the binary driver from Realtek is there a way to remove it if it makes things worse ?

00:00.0 Host bridge: Intel Corporation Mobile GME965/GLE960 Memory Controller Hub (rev 0c)
00:02.0 VGA compatible controller: Intel Corporation Mobile GME965/GLE960 Integrated Graphics Controller (rev 0c)
00:02.1 Display controller: Intel Corporation Mobile GME965/GLE960 Integrated Graphics Controller (rev 0c)
00:1a.0 USB controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #4 (rev 03)
00:1a.7 USB controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #2 (rev 03)
00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 03)
00:1c.0 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 1 (rev 03)
00:1c.1 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 2 (rev 03)
00:1c.5 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 6 (rev 03)
00:1d.0 USB controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #1 (rev 03)
00:1d.1 USB controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #2 (rev 03)
00:1d.2 USB controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #3 (rev 03)
00:1d.7 USB controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #1 (rev 03)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev f3)
00:1f.0 ISA bridge: Intel Corporation 82801HEM (ICH8M-E) LPC Interface Controller (rev 03)
00:1f.1 IDE interface: Intel Corporation 82801HM/HEM (ICH8M/ICH8M-E) IDE Controller (rev 03)
00:1f.2 SATA controller: Intel Corporation 82801HM/HEM (ICH8M/ICH8M-E) SATA Controller [AHCI mode] (rev 03)
10:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8191SEvA Wireless LAN Controller (rev 10)
30:00.0 Ethernet controller: Marvell Technology Group Ltd. 88E8042 PCI-E Fast Ethernet Controller (rev 10)

lsmod | grep rtl
rtl8192se 99989 0
rtlwifi 111202 1 rtl8192se
mac80211 506816 2 rtl8192se,rtlwifi
cfg80211 205544 2 rtlwifi,mac80211

Update : This seemed to occur under wifi load. Streaming youtube HD or running a repeated speedtest such as http://www.speedtest.bbmax.co.uk/

After which all connections were dropped even though network manager still showed connected via wifi. Could not connect to local router ip address. Needs to be rebooted. BTW win7 dual boot is fine.

Could someone please try Ubuntu 12.10 and see if the problem is still present there?

Also tests of newer mainline kernels would be useful.

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 1000208

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

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Shannon, thank you for reporting this and helping make Ubuntu better. Could you please provide the information following https://wiki.ubuntu.com/Kernel/LinuxWireless ?

1) didn't upgrade bios
2) encryption type: WPA2-PSK
3) AP: Buffalo WHR-G300N
4) no mac filtering
5) No idea now to check QoS WMM
6) other device does not have such problem with the same AP(s), including Windows 7 and mobile phones (iOS and Android)
7) this problem seems NOT related to the AP hardware. I have 2 APs, one is Buffalo the other is TP-LINK, on 2 floors, I have exchanged them, problem persists
8) this problem does not appear in 11.10 or earlier appears in 12.04 and gets better (happen less frequently) in 12.10
9) as this problem is intermittent, and I am using my laptop for daily work, it is quite difficult for me to test backport drivers etc, as:
a) the effect of the test (if goes smoothly) can be hard to observe, i.e. needs quite some days or weeks
b) if there is a problem I don't know if it could cause I have to reinstall the OS

I am sorry that the document is a bit complicated, and I think about 50% of the answers are already in the info I provided above.

If I can provide any more help please don't hesitate to contact me again.

Shannon, thank you for your comments. Could you please answer the following questions:
+ What is the full computer model number (ex. HP G32-301TX Notebook PC)?
+ What wireless connection type are you using (e.g. 802.11n, 802.11g, etc.)?

Model: G32-205TX (with RTL8191SE)

Connection type: AP supports 802.11n/g/b, I don't know the actual mode it is running, how do I check?

I also attach some screenshots of the AP configuration.

Shannon, thank you for your comments. As per http://bizsupport1.austin.hp.com/bizsupport/TechSupport/SoftwareIndex.jsp?lang=en&cc=us&prodNameId=5064629&prodTypeId=321957&prodSeriesId=4270017&swLang=13&taskId=135&swEnvOID=4062#120 an upgrade is available for your BIOS (F.27). If you upgrade to this, does it change anything?

Hi Christopher,

My BIOS version is F.23, I checked the link you gave me and unfortunately this stuff works for WINDOWS only, and most methods for Linux require a DOS based bios flash utility. My laptop is Linux only.

Also, my reporting that after upgrade to 12.10, the situation gets much better is based on my report on #21 above. The trick I did is that I setup 2 connections with same SSID but bind to specific AP. This way the symptom of get disconnected is rare, about 1 case in every 1 or 2 days, also, it is quite easy to get reconnected and get a long period of stable connection, that is to connect to the specific AP manually.

I don't know if it is my trick that makes situation better, or it is also related to upgrade to 12.10.

If you know how to flash bios under Linux, please let me know.

If there is a DOS based flash procedure, you can probably just make a USB stick with freedos and boot on that to do the flashing.

If there is a DOS based procedure, then no problem, but HP only provided a WINDOWS based procedure.

I can speed up the disconnect problem when running a torrent app such as deluge and downloading. It seems the amount of traffic makes the issue worse. Updated kernel, wifi backports and network manager to proposed but still occurs. Tried 150Mb and 300Mb wireless modes on router.

3.2.0-33-generic #52-Ubuntu SMP

David, if you have a bug in Ubuntu, could you please file a new report by executing the following in a terminal:
ubuntu-bug linux

For more on this, please see the Ubuntu Kernel team article:
https://wiki.ubuntu.com/KernelTeam/KernelTeamBugPolicies#Filing_Kernel_Bug_reports

the Ubuntu Bug Control and Ubuntu Bug Squad article:
https://wiki.ubuntu.com/Bugs/BestPractices#X.2BAC8-Reporting.Focus_on_One_Issue

and Ubuntu Community article:
https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette

When opening up the new report, please feel free to subscribe me to it.

Please note, not filing a new report may delay your problem being addressed as quickly as possible.

Thank you for your understanding.

OK, sorry about that... it was not my intention to hijack someone else's bug report. Just confirming this issue.

I had trouble with the apport program taking forever. I waited 30 minutes and it never finished gathering info so I killed it and gave up waiting. Can't believe it should take so long.

Anyhow.. I ended up installing kernel 3.5.0 from http://ppa.launchpad.net/upubuntu-com/kernel-amd64/ubuntu and wifi seems stable now. I have been running deluge torrent as a wifi stress test for a day now with no disconnects. So fixed upstream. Just hope 3.5 kernel is introduced in 12.04.2

3.5.0-030500-generic x86_64

David, if apport is giving you troubles, could you please file a new report via the website https://bugs.launchpad.net/ubuntu/+source/linux/+filebug ?

Hi,

I have been experiencing this bug as per above: heavy wifi traffic causes loss of connection and impossible to re-establish. Same machine booted to WIN7 has no problem.

machine: ASUS EEEPC 1201N
wifi: RTL8191SEvA

Are there any known work arounds?
Thanks,
Bob

gratefulfrog, if you have a bug in Ubuntu, could you please file a new report by executing the following in a terminal:
ubuntu-bug linux

For more on this, please see the Ubuntu Kernel team article:
https://wiki.ubuntu.com/KernelTeam/KernelTeamBugPolicies#Filing_Kernel_Bug_reports

the Ubuntu Bug Control team and Ubuntu Bug Squad team article:
https://wiki.ubuntu.com/Bugs/BestPractices#X.2BAC8-Reporting.Focus_on_One_Issue

and Ubuntu Community article:
https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette

When opening up the new report, please feel free to subscribe me to it.

Please note, not filing a new report may delay your problem being addressed as quickly as possible.

Thank you for your understanding.

Re : Are there any known work arounds?

Install the upstream kernel 3.5 if that is not an issue for you. Confirmed fixed for me. Kernel 3.0 is also ok on previous 11.10 ubuntu.

Bug affects me too, though I have RTL8191SEvB in my Lenovo Thinkpad.

Solved it in 12.04 and 12.10 by compiling the driver, but if I try it now on 13.04 it comes up with a lot of compile errors.

Very much still a problem; wifi pretty much unusable.

Chanchao, if you have a bug in Ubuntu, could you please file a new report by executing the following in a terminal:
ubuntu-bug linux

For more on this, please see the Ubuntu Kernel team article:
https://wiki.ubuntu.com/KernelTeam/KernelTeamBugPolicies#Filing_Kernel_Bug_reports

the Ubuntu Bug Control team and Ubuntu Bug Squad team article:
https://wiki.ubuntu.com/Bugs/BestPractices#X.2BAC8-Reporting.Focus_on_One_Issue

and Ubuntu Community article:
https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette

When opening up the new report, please feel free to subscribe me to it.

Please note, not filing a new report may delay your problem being addressed as quickly as possible.

Thank you for your understanding.

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]

I got this problem. It disconnects when the network is weak. It only reconnects if I use the following commands:
/sbin/rmmod rtl8192se ; killall NetworkManager; modprobe rtl8192se

I'm using ubuntu 13.04

Sergio Daniel Carvalho Canuto, if you have a bug in Ubuntu, the Ubuntu Kernel team, Ubuntu Bug Control team, and Ubuntu Bug Squad would like you to please file a new report by executing the following in a terminal:
ubuntu-bug linux

For more on this, please see the Ubuntu Kernel team article:
https://wiki.ubuntu.com/KernelTeam/KernelTeamBugPolicies#Filing_Kernel_Bug_reports

the Ubuntu Bug Control team and Ubuntu Bug Squad team article:
https://wiki.ubuntu.com/Bugs/BestPractices#X.2BAC8-Reporting.Focus_on_One_Issue

and Ubuntu Community article:
https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette

When opening up the new report, please feel free to subscribe me to it.

Please note, not filing a new report would delay your problem being addressed as quickly as possible.

Thank you for your understanding.

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]

Confirming that the workaround in #75 does the trick. Next time this happens, I'll file a new report as in #76. I'm not sure it it'll work though, as I have no network then.

I filed a new report over at bug #1238968.

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]