Wifi disconnects and my wifi is missing from list so I cannot connect to it

[florin]

For a few times a day, my wifi disconnects when using 802.11n. If I try to connect to it manually, I cannot do that as it is missing from the list with nearby connections. I have discovered a way to connect by going to Connect to hidden Wifi Connection, select the dropdown and chose from that list my home wifi network. It works. But of course, a few hours later, it will disconnect and I have to do this again. I should mention that my wifi is not a hidden one, never has been. See the attached screen recording.

Router: TP-Link TL-WR842ND v1; firmware: DD-WRT v24-sp2 (12/22/14) std (SVN revision 25697), Linux 3.5.7.33 #17743 Mon Dec 22 04:32:38 CET 2014 mips.

WORKAROUND: Use 802.11g.

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: linux-image-4.2.0-27-generic 4.2.0-27.32
ProcVersionSignature: Ubuntu 4.2.0-27.32-generic 4.2.8-ckt1
Uname: Linux 4.2.0-27-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.19.1-0ubuntu5
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: florin 1578 F.... pulseaudio
CurrentDesktop: Unity
Date: Mon Feb 8 21:04:27 2016
HibernationDevice: RESUME=UUID=e6dd3a64-131e-4aee-8ed4-84e81029859e
InstallationDate: Installed on 2016-01-30 (8 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
Lsusb:
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 002: ID 13d3:5652 IMC Networks
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: TOSHIBA SATELLITE P50-C
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-27-generic root=UUID=99542f8d-67cc-4ee6-bd91-596c9a4709ee ro persistent quiet splash
RelatedPackageVersions:
 linux-restricted-modules-4.2.0-27-generic N/A
 linux-backports-modules-4.2.0-27-generic N/A
 linux-firmware 1.149.3
SourcePackage: linux
UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/08/2015
dmi.bios.vendor: INSYDE Corp.
dmi.bios.version: 1.20
dmi.board.name: 06F4
dmi.board.vendor: FF50
dmi.board.version: Type2 - Board Version
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: OEM Chassis ManuFacturer
dmi.chassis.version: OEM Chassis Version
dmi.modalias: dmi:bvnINSYDECorp.:bvr1.20:bd10/08/2015:svnTOSHIBA:pnSATELLITEP50-C:pvrPSPUFE-001009G6:rvnFF50:rn06F4:rvrType2-BoardVersion:cvnOEMChassisManuFacturer:ct10:cvrOEMChassisVersion:
dmi.product.name: SATELLITE P50-C
dmi.product.version: PSPUFE-001009G6
dmi.sys.vendor: TOSHIBA

[Brad Figg (brad-figg)]

This change was made by a bot.

[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 v4.5 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/v4.5-rc3-wily/

[florin (florin-arjocu)]

I have tested the latest mainline v4.5 kernel for a few days and until right now, the bug did not occur. Until now, as it happened half an hour ago. It seems to happen a lot less often than old kernel, but it does. It might be a coincidence, cannot tell. At first, I would imagine it is a problem of the network manager, not a kernel bug, as the it can connect to the network, but it can only do that if I get to Connect to hidden wifi and select it from the dropdown list. It is strage my network shows there as it is not a hidden wifi network. I would think the network manager does not manage properly the detected networks.

[florin (florin-arjocu)]

Did not find where to add a 'kernel-bug-exists-upstream' tag.

[penalvch (penalvch)]

florin:
+ Regarding the scope of this report (Intel WiFi card) what was the earliest release this is reproducible with?
+ What is the router manufacturer, model, and firmware version?
+ Could you please re-test with the latest mainline kernel (4.5-rc4) and advise to the results?

[florin (florin-arjocu)]

I just installed the rc6, this is the latest version at this moment.

Answers to your reply:
- it is hard to say what was the earliest version this bug occurred, this is a new laptop and I only had it for the 2-3 weeks. What I can tell is that the bug was a bit different in the rc3 kernel from the above link; it only disconnected once or twice in a week, but despite that, internet stopped working for more times; I could not even connect to router IP or ping google (could not resolve host). Reconnecting made it work again (clicking the network in the network manager).
- Router: TP-Link TL-WR842ND v1; firmware: DD-WRT v24-sp2 (12/22/14) std (SVN revision 25697), Linux 3.5.7.33 #17743 Mon Dec 22 04:32:38 CET 2014 mips.
- as I said, I installed the latest version, rc6. Have to test it for a while before getting back here.
uname -a
Linux florin-SATELLITE-P50-C 4.5.0-040500rc6-generic #201602281230 SMP Sun Feb 28 17:33:02 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

[florin (florin-arjocu)]

It it helps: I usually saw the internet stopping when I was downloading torrents; after a short while, everything stopped. Cannot tell what the cause is, but in Windows 10 on this laptop I could download torrents and nothing stopped working. Maybe it is a coincidence, but I cannot tell (yet). I do not want to use Win at all, I switched about 5 years ago and I usually like Ubuntu.

[florin (florin-arjocu)]

Tested it. See the recording link on youtube.

This is how internet stops working on toshiba p50-c-18d: Reconnecting make it work again. It is easy to reproduce the bug by downloading a torrent. The thing is that internet stops working on mobile android also when it stops working on computer, it is like some kind of jamming; reconnecting make it work again on phone, too. Simply disconnecting the computer make the phone wifi internet work, so it is definitely caused by the computer. Not happening in windows 10 (or I could not reproduce it, will test again with a few torrents). This is with the latest kernel:

uname -a
Linux florin-SATELLITE-P50-C 4.5.0-040500rc6-generic #201602281230 SMP Sun Feb 28 17:33:02 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

This is the recording:
https://youtu.be/ocooPgw4Mnw

[penalvch (penalvch)]

florin, to clarify, are you using 802.11n or 802.11g when the disconnections happen?

[florin (florin-arjocu)]

The network is set to n-g mixed, but I think it works on n judging by the speed.

[florin (florin-arjocu)]

I also add the wifi Connection Information box, maybe it helps. If I can run any logging or debugging, please tell exactly what to do to make it work. Can't tell if it dynamically changes the n and g mode.

[penalvch (penalvch)]

florin, as per your screenshots, it's definitely using 802.11n.

However, could you please force the router to be in G only mode, and advise if this changes anything?

[florin (florin-arjocu)]

I forced the G mode and for now, 2 larger torrent downloads with no syncope. 2.2-2.7 MB/s.

[penalvch (penalvch)]

florin, speaking to the scope of this report of how the WiFi disconnects, are there any further disconnections while on 802.11g?

[florin (florin-arjocu)]

Christopher - no disconnects as far. I can only talk about latest kernels, did not go back to original distribution kernel as these are better.

[penalvch (penalvch)]

florin, given you said the disconnects happen within the day, let the test continue with 802.11g only until sufficient time has elapsed to conclude it's a complete WORKAROUND.

[florin (florin-arjocu)]

Christopher - I will allow it to work on G mode, it does not seem to be too slow for now. If I'll switch to 500 mpbs or gigabit internet contract it would be too slow, but for now it works fast enough.

Bye the way, the original wifi driver did not work well at all, I got some errors; you should get the newer ones from newer kernels. I got the one from Intel to make it work with original distribution kernel.

[penalvch (penalvch)]

florin:

>"Bye the way, the original wifi driver did not work well at all, I got some errors; you should get the newer ones from newer kernels. I got the one from Intel to make it work with original distribution kernel."

The problem here is that not enough information is being provided upfront to understand what is being tested precisely. Hence:
1) Where did you get this newer driver precisely (URL, version specifically, etc.)?
2) Were you using this alternative driver when you first reported this issue?

[florin (florin-arjocu)]

1. I copied this one to /lib/firmware: https://wireless.wiki.kernel.org/_media/en/users/drivers/iwlwifi-7265-ucode-25.30.14.0.tgz
(http://www.intel.com/content/www/us/en/support/network-and-i-o/wireless-networking/000005511.html)

2. Yes. Could not use system with original distribution kernel driver, some error occurred, don't remember which one. Found a solution online and with the above or next kernels it seems to be working. I use the computer for working, cannot keep it for looking at it, as a beautiful object. :)

[florin (florin-arjocu)]

(1. copied the content of archive)

[penalvch (penalvch)]

florin, to get a stable baseline, could you please test http://cdimage.ubuntu.com/daily-live/current/ and advise to the results?

[Launchpad Janitor (janitor)]

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