Wifi problems with Nov 2023 Linux

[theypsilon]

It seems like some users are experiencing problems with this wifi dongle after upgrading to the latest Linux version. It's a pretty popular wifi dongle, and it worked fine with previous Linux versions.

[sorgelig]

In exactly latest update there was no change in wifi drivers. There were changes in previous updates.
So it's strange

I have this wifi dongle somewhere. I will try to find it.

[sorgelig]

Ok. Found that dongle. Latest linux.img, zImage_dtb.
WiFi works fine.

[theypsilon]

Pretty strange indeed. This user who agreed to do rigorous testing could reproduce this in two different setups. He doesn't see the wifi icon showing up at all; it only shows if he also has ethernet connected. I'm trying to convince another user to do such tests. I don't have the dongle, unfortunately.

[sorgelig]

I've rechecked with ethernet disconnected. Still works.
One thing: i never used mr.fusion. Neither i use updater because i need special setup due to developing.

Basically my SD card is formatted by this installer. And then i update linux by simple replacing of linux.img and zImage_dtb.

[theypsilon]

The test flow this user is doing is:

• Format with Mr.Fusion
• Boot with no ethernet, check wifi works
• Run updater without updating linux: Create downloader.ini and write

[MiSTer]
update_linux = false

• Reboot, check wifi still works
• Remove downloader.ini (or change option to true) and run updater again to upgrade linux
• Reboot with no ethernet, wifi doesn't work

It could be that the Mr.Fusion step is relevant here somehow

[birdybro]

@theypsilon Ask that user if they use ganged SSIDs for 2.4ghz and 5ghz (meaning their Router is setup to have one WiFi network for both 2.4ghz band and 5ghz band). The wifi update in August from @gkrzystek enabled 5ghz for that chipset (Realtek 8821CU, VID:PID 0BDA:C820), and I've had issues with linux desktops before handling ganged SSID.