After more than 4 months testing new things every single day, I think I
figure out a fix. It's been only 2 days of testing but I guess many
people are anxious needing a fix, so I'm already reporting this so
others can help test.

First I will point out the major tests that don't help:
1. None of the i8042 quirks alone or combined, or combined with pnpacpi=off or 
combined with atkbd.reset or atkbd.softrepeat=1,
2. Compiling the kernel with any of the different preempt models, nor the Clean 
Linux tweaks for performance,
3. Any combination of acpi_osi=! acpi_osi="Windows XXXX",
4. Moving irq1 to the performance core and increasing the priority of ksoftirqd 
(echo 0 > /proc/irq/1/smp_affinity_list + chrt -f -p 99 14 $(pgrep -f 
"ksoftirqd/0"),
5. Completely disabling C-States or combining it with disabling P-States,
6. Disabling Bluetooth or the Wifi radio or both.

This one seems to make things even worse: threadirqs
This one seems to help a little: irqpoll

What may fix (needs more testing, currently it's been only 2 days of no random 
key repeat):
Disabling atom cores (e-cores)
Currently I'm combining it with these other tweaks that I'm not sure are 
necessary: FastBoot=Thorough + Hyperthread=disabled + atkbd.reset i8042.reset 
i8042.nomux i8042.noaux i8042.noloop

Step by step on how to safely apply it:
1. Add `atkbd.reset i8042.reset i8042.nomux i8042.noaux i8042.noloop` to boot:
sudo vim /etc/default/grub
and change GRUB_CMDLINE_LINUX_DEFAULT. Mine looks like this:
GRUB_CMDLINE_LINUX_DEFAULT="nowatchdog cpufreq.default_governor=performance 
atkbd.reset i8042.reset i8042.nomux i8042.noaux i8042.noloop"
sudo update-grub

2. Check if BIOS advanced mode is enabled:
sudo cat 
/sys/class/firmware-attributes/dell-wmi-sysman/attributes/AdvancedMode/current_value
- If it is disabled, then enable it:
echo "Enabled" | sudo tee 
/sys/class/firmware-attributes/dell-wmi-sysman/attributes/AdvancedMode/current_value

3. Enter BIOS (reboot and press F2 when the Dell logo appears), and change this 
settings:
- Pre-boot Behavior > FastBoot = Thorough
- Performance > Multiple Atom Cores = 0
- Performance > Intel® Hyper-Threading Technology = off

It would help if more people test and confirm these changes fix the issue. 
I guess these changes point to a cause for the random key repeat: too much 
variance on latency, jitter.

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2093376

Title:
  Random keys "stick" repeating until any key is pressed

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux-signed-hwe-5.15/+bug/2093376/+subscriptions


-- 
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to