Friday, 29 November 2013

Intel 7260 wireless stops working / is dropping in kernel versions 3.11/3.12

I'd recently been having trouble with the Intel 7260 wireless card in my laptop with these kernels. There were several manifestations of the problem:

  • With powersaving on the card would repeatedly drop and eventually reconnect under kernel 3.12
  • With powersaving off and connected in ac mode the card would frequently (but very quickly) drop authentication, then reauthenticate with the network. This mostly manifested in the form of freezes in audio/video conversations, and was visible in dmesg.
  • With powersaving off and connected in bgn mode the wireless would work pefectly for a certain amount of time, and then stop. Wireless would still show as connected, but there would be no network traffic. Fixing this required turning the network interface off and on again.
There are several bugreports up for this card in Bugzilla at the moment, so I decided to try pulling in some more up-to-date iwlwifi code from the compat-wireless backports repository. A guide on compiling and installing these can be found here or in the answer here.

The long and short of it is, in the dir with the tarball:
tar -xvf backports-*.tar.gz
cd backports*
make defconfig-iwlwifi
make -j2
sudo make install    
After building and installing the compat wireless for kernel 3.12.1, my current running kernel (you can determine yours with uname -a) I've found the experience to be much better so far, no irritating drops to date.

Sunday, 24 November 2013

Frequent pauses/freezing in Gnome Shell/Ubuntu 13.10 with Sandy Bridge

While doing any graphics heavy task, such as playing a game or just watching Netflix via pipelight I was getting frequent pauses, where the entire system would lock up for ~5 seconds.

Dmesg was showing the following whenever it happened:

[drm:i915_set_reset_status] *ERROR* render ring hung inside bo 3.11

It turns out this is related to a bug in Mesa, which has been fixed in 10.0. To update to this in Ubuntu 13.10, add this repository:

sudo add-apt-repository ppa:oibaf/graphics-drivers
sudo apt-get update && sudo apt-get dist-upgrade
and restart.

Be aware that while these packages seemed stable for me, they could well result in system instability for others. Make sure you know what you're doing and have a recovery plan, or backups should you need to revert. Something like PPA-Purge is likely the trick.

Skype not using Pulseaudio in Linux Mint 16 Cinnamon 64 bit

Another quick one. I was having trouble with Skype in the recent Linux Mint 16 RC with Cinnamon 2.0 (an otherwise fantastic release). Skype was showing a long list of audio devices and utilising Alsa, which was causing some problems when other sound events occurred via Pulse.

To fix, just run:

sudo apt-get install libpulse0:i386
And restart Skype, hopefully that's that.

Sunday, 17 November 2013

Bad Overview performance in Gnome 3.8? Try re-enabling UXA on your Intel card

After upgrading to Ubuntu Gnome 13.10 recently, I was struck by how much worse graphical performance was in the overview, and was greatly disappointed, as I've been using Gnome on 12.04 for a very long time now without difficulties.

On a hunch I re-enabled UXA for the Intel graphics chip in place of SNA, and the difference is night and day - pretty much on par with what it was before. This is using a Sandy Bridge i7-2670QM, HD 3000 cpu.

To do so:

sudo nano /usr/share/X11/xorg.conf.d/20-intel.conf
Paste in the following text (ctrl + shift + v):
Section "Device"
   Identifier  "Intel Graphics"
   Driver      "intel"
   Option      "AccelMethod"  "uxa"
Ctrl + X to exit and save, then reboot.

Edit: I've additionally found that after upgrading to Kernel 3.12.1 overview performance has increased again.

Saturday, 16 November 2013

Monodevelop crashes on startup in Linux Mint 16/Ubuntu 13.10

Nice and easy one this time round, looks like the dependencies on the package aren't set properly:

sudo apt-get install libmono-cairo2.0-cil
That should sort it.