Comment 36 for bug 1673344

Revision history for this message
Simon Ye (yesimon) wrote : Re: Ubuntu 16.04 doesn't recongnize wifi card after loosing signal completely (intel 7260) even when I try to restart network manager

Final update on this. It turned out that using the 2.4 Ghz band was much more stable than 5 Ghz, which got wedged within minutes, but conditions eventually worsened until even on 2.4 Ghz without much internet usage it would get wedged every few hours. I then tried out various kernel versions on 16.04 LTS going all the way back to 4.4.9 and different versions of iwlwifi ucode with no success and different variations of dmesg output, even though I recalled the wifi working just fine back before upgrading to 17.10.

Looking through other bugs, this one is very similar https://bugzilla.kernel.org/show_bug.cgi?id=191601 and there is a script that worked for me to reset the wifi without having to reboot, which was a major improvement.

Clearly there wasn't a specific recent software change in Linux that caused this issue. Other people reporting this bug have reported it cropping up at different OS/kernel versions. The wifi still works perfectly fine on Windows 10, and the script to remove/re-add the PCI card via sysfs can recover the wifi. Based on all of these facts, I believe this is a longstanding hardware-software bug in Linux where it can't recover from certain conditions when there is hardware degradation on the PCI card - perhaps some timeout deadlock - that Windows either shrugs off or can recover from. Based on that hunch, I ordered a new 7260 half height PCI-E card, replaced it in my desktop, and wifi has been working perfectly since (a week or so).

At this stage, this card is very old and no specific bug can be easily pinpointed. Furthermore it requires a somehow hardware degraded 7260 card to reproduce so a fix will be unlikely. In my opinion it is your best shot to buy a replacement 7260 card to tide you over until you upgrade your PC.