I have an old-ish laptop with Fedora 42, which I tend not to update very often. So I just did it now, after several weeks, and everything seemed to go fine. But now, without changing anything else (same router, same settings, etc), the wifi is horrible: each 30 seconds after connecting, I get a “wpa_supplicant timed out” error message. Wifi disconnects, and sometimes it reconnects automatically, only to disconnect about 30-35 seconds later.
Of course, trying to boot into a previous kernel seems not to do anything: the connection still drops, making it very hard to do useful stuff with it.
I don’t see what could have caused it, and especially why falling back to a previous kernel wouldn’t solve it.
Google shows some people using iwd, but I’d really like not having to spend hours trying to fix something that worked 10 minutes ago. Is there some reasonable explanation on what might have happened, and how could I just rollback? Should I try downgrading a specific package? I can check the dnf logs to get package versions, if that can help.
Well ok, I ended up replace wpa_supplicant with iwd after all… it survived slightly longer, but after about 300 seconds, once again the connection was lost. And then it lasted only about 80 seconds.
Are there other obvious packages I should try downgrading? I’m out of ideas for now.
Otherwise, should I get a wifi dongle to avoid Atheros-related issues? If so, which brand would be better for Linux? (my wifi card has no 5 GHz, only 2.4 GHz, so if getting a USB dongle might provide that, it could be worthwhile… as long as the dongle doesn’t have the same issue.)
Many seem to have issues with qualcomm wifi cards, similar to what you describe. It appears to be mostly driver and/or hardware issues.
A wifi dongle would be good, as long as you make certain it has a chipset that is supported in linux. The intel chipsets seem to be almost 100% supported. The dongle would also give you the additional bandwidth of 5 GHz in addition to 2.4 GHz. If the advertised specs do not provide the chipset info (many do not) then it is best to avoid that device.
Almost every device that is made today supports both 2.4 & 5 GHz wifi.
Well it stopped working again, and the same modprobe settings are useles now. Extremely annoying. I wonder if the hardware itself is defective, but I don’t know how to check it. It’s really frustrating when just updating packages breaks something that badly. Even updating the kernel and all Fedora packages has no effect whatsoever now.
There are often issues with WiFi after updates, so I have found it important to have a USB dongle with reliable in-kernel support. Consult Linux USB WiFi Adapters to find good models.
Note that many systems have minimal WiFi drivers loaded at boot to support installation/updating in cubicle farms. These can need a vendor firmware update with newer kernels. If you don’t need WiFi at boot, some issues may be avoided if you can disable WiFi in UEFI/BIOS.boot. That may, however, require an extra step after booting to enable wifi.
Ok, so I ended up getting an Intel internal wifi card and replacing the other one. For now it seems to work, despite a missing antenna (the old one was 2.4 GHz only, with a single antenna, while the new one also has 5 GHz).
Still a bit annoyed by the fact that it all seems to have been triggered by an update and I couldn’t roll back.
Just a comment. Leaving the 5GHz port open without an antenna can cause damage to your wifi card depending how clever the design is. The antenna is impedance matched to the port, which could be 50 ohm or more likely 300ohm. Having the antenna port open throws all the RF energy back into the card heating things up nicely, unless the card has a ability to auto reduce the power on that band. You should be able to cheaply purchase a Laptop 5GHz antenna via ebay or similar.
Linux updates are driven by the need to support current hardware, to fix bugs, and to improve security. These changes can conflict with older drivers (kernel modules), and may require changes to vendor firmware. Vendors would rather that you buy new hardware, so support for older hardware is not a priority. We are left with compromises such as USB dongles.