Re: Suspend/resume issues with Mediatek MT7961 wifi card

On Sat, Oct 16, 2021 at 7:23 PM Maxim Levitsky [off-list ref] wrote:

I recently bought an Aya Neo tablet which now has this wifi chipset in its latest 2021 hardware revision.

I am using kernel 5.15.0-rc4 (compiled from source), and I also merged in it and tested the master branch of git://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless-testing.git

I tested with and without wireless running before suspend (using gnome's wireless disable option in the gnome's menu).

In all cases, the wireless card dies after the resume, which itself takes a lot of time most likely due to timeouts in the resume handler of this driver, and then the system is also partially hung.

Looks like the driver's resume (or suspend) function isn't working correctly, and dmesg also indicates several failures.

I had attached the full dmesg after a single suspend/resume cycle showing those errors.

If I unload the mt7921e prior to suspend and load it after, there are no errors, no timeouts, and wifi connects and works fine after resume.

My distro is Fedora 35 beta. Bluetooth also used to fail sometimes after resume when I used older Fedora versions, but now it seems very robust, and doesn't need any disabling, reloading of btusb/etc.

I am a kernel developer (I work on KVM these days), and I can test any patches/workarounds/firmware/etc when I find some time for that.

Best regards,
    Maxim Levitsky

(resend using plain text - reminds me to never use Gmail's web interface.)