[patch included]Slow speed and dropped connections with Realtek RTL8192CU-based wifi

[Patrick Then]

EDIT(other user): Some one fixed it in github, still works in at least in linux 4.4-4.11
https://github.com/pvaret/rtl8192cu-fixes
EDIT:

I am using a D-Link DWA-131 USB wlan adapter to connect to my private wlan.
The adapter works fine under Windows and I have no problems connecting to my wlan with other devices (e.g. my laptop running Linux Mint).
However, the adapter, which is based on the Realtek rtl8192cu chipset, won't work correctly on any current Ubuntu machine (in my case Kubuntu 15.10 64bit):

As also showcased by a myriad of other bug reports (most of which have expired by now), wlan-adapters based on the Realtek rtl8192cu chipset exhibit very slow connection speeds and frequently dropped connections with current Linux kernels.
I have noticed this originally in Linux Mint 17 running kernel 3.19.x, in Kubuntu 15.10 up to 4.2.0.35 and can confirm that it is still present in a live session of Xenial Xerus (16.04).
I have tried commonly mentioned "fixes" such as deactivating hardware encryption without success.

The drivers available on the Realtek homepage are apparently intended for older kernels and won't install.

There is, however, a fixed driver available via github (https://github.com/pvaret/rtl8192cu-fixes).
I have followed the instructions found there and finally my wlan-adapter is working correctly.
Apparently the issues caused by the broken driver in the linux kernels might be connected to power management.

I am posting this bug here in the hope that some developer finally manages to incorporate the (obviously available) fixes found in the github-drivers into the drivers already included in the kernel.
---
ApportVersion: 2.19.1-0ubuntu5
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: patrick 2300 F.... pulseaudio
 /dev/snd/controlC1: patrick 2300 F.... pulseaudio
DistroRelease: Ubuntu 15.10
HibernationDevice: RESUME=UUID=28c49a78-8b93-495e-bc1b-22c87db4734c
InstallationDate: Installed on 2015-10-22 (181 days ago)
InstallationMedia: Kubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
MachineType: Gigabyte Technology Co., Ltd. GA-870A-UD3
NonfreeKernelModules: fglrx
Package: linux (not installed)
ProcFB: 0 VESA VGA
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-35-generic root=UUID=1016b861-fa27-4990-bac9-58a3ab27ff5b ro quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 4.2.0-35.40-generic 4.2.8-ckt5
PulseList:
 Error: command ['pacmd', 'list'] failed with exit code 1: Home directory not accessible: Permission denied
 No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
 linux-restricted-modules-4.2.0-35-generic N/A
 linux-backports-modules-4.2.0-35-generic N/A
 linux-firmware 1.149.3
RfKill:

Tags: wily
UdevLog: Error: [Errno 2] Datei oder Verzeichnis nicht gefunden: '/var/log/udev'
Uname: Linux 4.2.0-35-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:

_MarkForUpload: True
dmi.bios.date: 08/01/2011
dmi.bios.vendor: AwardAward (授与する, じゅよする, juyosuru) Software International, Inc.
dmi.bios.version: F5
dmi.board.name: GA-870A-UD3
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.modalias: dmi:bvnAwardSoftwareInternational,Inc.:bvrF5:bd08/01/2011:svnGigabyteTechnologyCo.,Ltd.:pnGA-870A-UD3:pvr:rvnGigabyteTechnologyCo.,Ltd.:rnGA-870A-UD3:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvr:
dmi.product.name: GA-870A-UD3
dmi.sys.vendor: Gigabyte Technology Co., Ltd.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1572698/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Brad Figg (brad-figg)]

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

apport-collect 1572698

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.

[Patrick Then (patrickthen)]

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[Patrick Then (patrickthen)]

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[Patrick Then (patrickthen)]

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[Patrick Then (patrickthen)]

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[Patrick Then (patrickthen)]

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[Patrick Then (patrickthen)]

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[Patrick Then (patrickthen)]

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[Patrick Then (patrickthen)]

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[Patrick Then (patrickthen)]

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[Patrick Then (patrickthen)]

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[Patrick Then (patrickthen)]

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[Patrick Then (patrickthen)]

As requested, I've added the logs.
Just in case that I've previously installed the fixed driver from github.

Some quick testing via a live session indicates that the problem persists in Xenial, which I will probably install today or tomorrow.
I could provide additional info from there as well, if necessary.

[Patrick Then (patrickthen)]

I've now switched to Kubuntu 16.04 (64 bit, clean install) and can confirm that the problem is still there.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.6 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.6-rc6-wily/

[Patrick Then (patrickthen)]

To be honest, I'm a bit reluctant to do so, as it is my main (productive) system that is affected.
I'll think about it.

[Patrick Then (patrickthen)]

Ok, decided to install it, but noticed that the available 4.6 kernels behind the link are all for Wily, while I've since switched to Xenial (see comment #17), which still suffers from the same issue (with Kernel 4.4).

[bingo (stefandrude)]

I wish to keep this bug alive. I have the same problem, and I am looking for a solution.

[Patrick Then (patrickthen)]

@bingo:
If you don't mind, you can install the fix from the link in my OP.
Obviously, that's not an ideal solution, though, as it should be fixed in the kernel, rather by applying an external patch.

In principle, I'd still be willing to provide any additional informations (or install a 4.6 kernel, but there don't seem to be any mainline 4.6 kernels for Xenial, currently).

Anyway, I've used a cable for the last few weeks, but given that there hasn't been any further dev feedback recently, I'm probably going to install the fix from my OP again myself, to get rid of the cable and back to wifi.

[bingo (stefandrude)]

@Patrick:
Well, thank you very much for your offer. I am surprised nothing has changed given that the bug appears to have been around for some time.

For the time being I have switched back to an adapter using the Atheros AR7010+AR9287 chipset, which used to have a problem in the past and was the main reason to get an RTL8192cu based adapter in the first place.

[Launchpad Janitor (janitor)]

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

[Patrick Then (patrickthen)]

Expired or not, the problems persist...

[Patrick Then (patrickthen)]

This bug has never been fixed and is still there on Ubuntu 16.04 and up.
I'll gladly provide more data if finally someone is willing to actually look into it.

[Patrick Then (patrickthen)]

To be more precise: I'm currently running Kubuntu 16.10 with kernel 4.8 and still this adapter is not working right.
There obviously is a fix available (see my OP) it just needs some dev to include it into the kernel.

[Launchpad Janitor (janitor)]

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

[mike (mike5346874)]

i'm using the fix from git hub on 16.04 all up to date.
https://github.com/pvaret/rtl8192cu-fixes
Tried and work on kernels 4.4 , 4.8 and 4.11 .
I haven't tested it on 4.9 and 4.14

It's ALREADY fixed, some one just needs to review it's not malware and then do a copy paste.... -_-

Why it's not integrated alredy in the kernel after all this time????

[Kai-Heng Feng (kaihengfeng)]

What's the error message from rtl8xxxu?

[Patrick Then (patrickthen)]

I'm currently not using the adapter since I've moved to a new apartment where it's easily possible to connect via cable to the lan.
I don't remember there being any errors though.
Seriously guys, the solution is available on github, I linked it over one year ago, all the necessary information should be there.

[Kai-Heng Feng (kaihengfeng)]

Unfortunately "all the necessary information" needs to be merged into rtl8xxxu driver. Please file an upstream bug or ask maintainers on mailing list.

[Diary Entry (unabletoname)]

It effects me.