Frequent disconnects with Intel 8260 wireless NIC

[Craig G]

This issue has been resolved upstream and is described in
https://bugzilla.kernel.org/show_bug.cgi?id=117391

The current Ubuntu Xenial Xerus kernel (4.4.0-21.37) is built with a version of the iwlwifi driver which supports firmware version up to iwlwifi-8000C-19.ucode. However, the matching linux-firmware package ships with the -16.ucode version of the firmware, which contains this bug.

The next stable version of the firmware after -16.ucode is -21.ucode, but is not supported by the version of the iwlwifi driver in the 4.4.0 kernel. In order to fix this issue, either the minor version of the firmware (-19.ucode) needs to be included in the linux-firmware package or the iwlwifi driver in the kernel package needs to be upgraded with a backport of the iwlwifi driver new enough to support the -21.ucode firmware.

[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 1577800

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.

[Craig G (cgallek)]

Please see the upstream bug report for all of the necessary debugging logs. However, the bug has already been identified and the issue here is really just deciding how to package the fix.

[penalvch (penalvch)]

Craig G, to clarify, you tested the upstream firmware and confirmed it fixes the issue for your hardware?

[Craig G (cgallek)]

It did indeed fix the problem I was seeing in this bug report. However, I started having another less frequent issue shortly after (also disconnects, but completely different errors). I was only able to solve that one by getting the newest firmware (-21.ucode) AND rebuilding the iwlwifi modules with the latest version of the upstream driver code. I'm not sure exactly which change in the driver fixed my issue, though.

[penalvch (penalvch)]

Craig G:
>"...AND rebuilding the iwlwifi modules with the latest version of the upstream driver code."

Could you please advise either which mainline kernel or up to which commit specifically?

[Craig G (cgallek)]

I used version Core18 of the iwlwifi backports repository:
https://git.kernel.org/cgit/linux/kernel/git/iwlwifi/backport-iwlwifi.git/log/?h=release/LinuxCore18

and the current ubuntu 4.4 kernel with the following dkms.conf:
MAKE="'make' -j 12 KERNELDIR=/lib/modules/${kernelver}/build"
CLEAN="/bin/true"
PACKAGE_NAME=iwlwifi
PACKAGE_VERSION=Core18
REMAKE_INITRD=yes

BUILT_MODULE_NAME[0]=compat
BUILT_MODULE_LOCATION[0]=compat
DEST_MODULE_LOCATION[0]=/kernel/compat

BUILT_MODULE_NAME[1]=cfg80211
BUILT_MODULE_LOCATION[1]=net/wireless
DEST_MODULE_LOCATION[1]=/kernel/net/wireless

BUILT_MODULE_NAME[2]=mac80211
BUILT_MODULE_LOCATION[2]=net/mac80211
DEST_MODULE_LOCATION[2]=/kernel/net/mac80211

BUILT_MODULE_NAME[3]=iwlwifi
BUILT_MODULE_LOCATION[3]=drivers/net/wireless/intel/iwlwifi
DEST_MODULE_LOCATION[3]=/kernel/drivers/net/wireless/intel/iwlwifi

BUILT_MODULE_NAME[4]=iwlmvm
BUILT_MODULE_LOCATION[4]=drivers/net/wireless/intel/iwlwifi/mvm
DEST_MODULE_LOCATION[4]=/kernel/drivers/net/wireless/intel/iwlwifi/mvm

BUILT_MODULE_NAME[5]=iwlxvt
BUILT_MODULE_LOCATION[5]=drivers/net/wireless/intel/iwlwifi/xvt
DEST_MODULE_LOCATION[5]=/kernel/drivers/net/wireless/intel/iwlwifi/xvt

[penalvch (penalvch)]

Craig G, given you have tested iwlwifi-8000C-19.ucode with the Xenial kernel and found this to work out well, then it would appear the path of least resistance would be to backport to linux-firmware in Xenial.

[penalvch (penalvch)]

Craig G, while booted into the default Xenial kernel, but with iwlwifi-8000C-19.ucode, could you please execute the following command only once, as it will automatically gather debugging information, in a terminal:
apport-collect -p linux 1577800

[Craig G (cgallek)]

I'm not sure I would say it worked well, but it did fix one of two problems. The second was only fixed after both driver and firmware upgrades. I'm no longer running the 19.ucode version. Would apport data for the 21 version with the updated driver be useful?

[penalvch (penalvch)]

Craig G, unfortunately no because apport doesn't include useful data when using a non-default Ubuntu kernel. It would be best to do to as requested.

[bitinerant (bitinerant)]

Would someone be so gracious as to detail the workaround for this bug until it is fixed? I disabled secure boot and tried to build Core18 using instructions from the wireless.wiki.kernel.org page but I still have firmware 16.242414.0 and my WiFi continues to disconnect. Here is a summary of the steps I followed:

  cd /tmp/
  git clone https://git.kernel.org/pub/scm/linux/kernel/git/iwlwifi/backport-iwlwifi.git -b release/LinuxCore18
  cd backport-iwlwifi/
  make defconfig-iwlwifi-public
  sed -i 's/CPTCFG_IWLMVM_VENDOR_CMDS=y/# CPTCFG_IWLMVM_VENDOR_CMDS is not set/' .config # see web page subheading "About vendor commands"
  make -j4
  sudo make install # displayed lots of SSL errors
  # reboot

It appears that I have the updated module but it's not getting loaded:

$ sudo find /lib/modules/$(uname -r) -name iwlwifi.ko -ls
  1244072 352 -rw-r--r-- 1 root root 359590 Oct 26 23:29 /lib/modules/4.4.0-47-generic/kernel/drivers/net/wireless/iwlwifi/iwlwifi.ko
  1305660 536 -rw-r----- 1 root root 545328 Nov 14 18:55 /lib/modules/4.4.0-47-generic/updates/drivers/net/wireless/intel/iwlwifi/iwlwifi.ko

[bitinerant (bitinerant)]

I updated to kernel 4.8 by installing 'linux-generic-hwe-16.04'. Now ethtool reports firmware 22, so I think my problems are solved, but this doesn't help people on the LTS kernel 4.4.

[penalvch (penalvch)]

Craig G, could you please advise if the updated kernel and linux-firmware via the Ubuntu repositories fixes your issue?

[Craig G (cgallek)]

I haven't had any problems since upgrading to yakkety:
4.8.0-30-generic #32-Ubuntu
driver: iwlwifi
version: 4.8.0-30-generic
firmware-version: 22.361476.0

[penalvch (penalvch)]

Craig G, this bug report is being closed due to your last comment https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1577800/comments/14 regarding this being fixed with an update. For future reference you can manage the status of your own bugs by clicking on the current status in the yellow line and then choosing a new status in the revealed drop down box. You can learn more about bug statuses at https://wiki.ubuntu.com/Bugs/Status. Thank you again for taking the time to report this bug and helping to make Ubuntu better. Please submit any future bugs you may find.