Wifi unstable - package drops

First of all:

Device: Rasp Pi 2
Installation media: SDcard
Connection: (Wired,) Wifi
Power Supply Type: Samsung and Goobay
Power specs: both 2A
Peripherals: Wifi-dongle, (wireless mouse)
Storage Device (incl. Network Sharing Protocol): none
OSMC version: 2015.07-1
XBMC version: (15.1-RC1 Git:Unknown). Platform: Linux ARM (Thumb) 32-bit
Codecs: none
Audio/Video Output: HDMI
Overclocked: no
Config.txt Extras:
LINK to uploaded logs in pastebin: http://paste.osmc.io/lutehisoru

Ok, here’s the story…
I have a Pi2 with a hifiberry-addon. Until two weeks ago everything works fine. I was connected via wifi and no interupts (ok, once a week, but a reboot helped). About two weeks ago the wifi stopped working. I got constant package drops. Connected with LAN works. You can see at the first screenshot how dmesg looks like and pings from my laptop.
Some days after osmc-update 2015.07-1 released.
I updated and tried again. Since then I have the GPIO_IN=08-spam problem ( Logging SPAM (GPIO_IN=08) - #28 by vanMacG ). The package drops are still the same although I can’t find them in the dmesg anymore (see also screenshot two).

What I already tried:

  • Switch the power supply
  • max_current-option in piconfig
  • demount hifiberry

Any ideas on this issue? Thanks for helping!

screenshot 1:

screenshot 2:

It looks like you have a different chipset to the log spam poster. lsmod and dmesg will confirm this.

The log spam problem should not impact performance


Whenever a properly working wifi setup goes down the tubes with no apparent changes (same hardware, no software updates etc) my first suspicion is always going to be wifi interference from a new wireless router at a neighbours, or your neighbours or your own router have switched channels and are now conflicting with each other.

A lot of routers default to “auto” for the channel which means every time they’re powered on they will scan to try to work out what channel has the least traffic, so you will typically end up on a different channel whenever the router boots, and some may be far from optimal. Likewise your neighbour could have a router set to auto and they rebooted their router and now it is broadcasting on top of yours. Or they have simply started using it a lot more thus generating more interference. (Maybe they are torrenting now)

I would start by doing speed tests to another device near the Pi to see if there is packet loss and slow speeds to another device, I would also try changing channels on the router - try 3 or 4 different channels to see if there is a difference. Do a google search on general wifi troubleshooting techniques - most of them will apply to OSMC as much as it will any other system.

Thank you both for your reply!

@sam_nazarko: dmesg should be in the pastebin from 1st post: http://paste.osmc.io/lutehisoru
Here is a screenshot of lsmod. Can I do anything to assist in tracking down the log-spam issue? You said it is from “upstream”, can/should I file a bugreport anywhere?

@DBMandrake: That was indeed a problem when I got my Pi two month ago. I used inSSIDer to track this down and changed the wifi channel. I though it could be a Linux/OSMC problem because after the update I don’t see the packet losses in dmesg anymore… My laptop is 2m away from the Pi and works with max spped and no packet losses.
Nevertheless I gave it a try. First I set up a virtual wifi with my laptop and the Pi connects without problems and had no packet loss… Damn Wifi-Router… I switched channel at the router again, and now the Pi is connect for already 15 minutes withous packet loss. According to inSSIDer both channels are with no conflicts…

So almost certain this was caused by my wifi router… hope that it works now, otherwise I have to buy a new one… :-/

A lot of things other than Wifi also use the 2.4Ghz ISM band, including microwave ovens, some cordless phones, bluetooth, some baby monitors, and most notably, wireless HDMI senders.

None of the above will show up on inSSIDer as they are different protocols to wifi, so one of them could be causing major interference to certain channels and inSSIDer or any other basic wifi scanner would show everything was clear. Only with one of the more advanced spectrum analyser systems would you see the interference, as those systems can detect any type of transmission within a frequency range regardless of what it is.

I mention wireless HDMI senders as when I was doing tech support for an ISP it was actually a pretty common problem - when turned on some of them completely wipe out wifi on some channels to the point where there is massive packet loss and unusable throughput. Many wifi routers default to automatic channel selection but they too cannot detect non-wifi interference so will happily select a channel that is being wiped out by an HDMI sender…