Random key repeat problem until another key is pressed

Question

My laptop is Dell's Inspiron 3530.

I have this problem with the keyboard since the first day the notebook arrived, five months ago. It happens 1 to 5 times a day. I can't figure out any trigger.

It happens with the "official" Dell's Ubuntu, but also with Debian and I saw reports of it happening in Fedora too.

I tried many many things to fix, none helped.

The summary of the major tests I did that doesn't fix the problem:

1. None of the i8042 quirks alone or combined, including i8042.dumbkbd, 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,
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 $(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.
7. This one seems to make things even worse: threadirqs
8. pcie_aspm=off
9. changing Power > Thermal from "ultra-performance" to "cool" + disabling SpeedStep
10. Disabling intel turbo
11. notsc
12. i915.enable_sagv=0 (fails to finish booting)
13. i915.enable_psr=0 i915.enable_fbc=0
14. isolcpus=11 and echo 11 > /proc/irq/1/smp_affinity_list
15. pci=nocrs (doesn't boot)
16. pci=nomsi
17. isolcpus=4 acpi_irq_nobalance atkbd.softrepeat + disable function keys at BIOS
18. BIOS Power > Thermal > "ultra-performance" -> "optimized" + echo 75 > /sys/devices/system/cpu/intel_pstate/max_perf_pct

Please ANY help would be deeply appreciated.

desgua · Answer

As one can see on comment #69 here: https://bugs.launchpad.net/ubuntu/+source/linux-signed-hwe-5.15/+bug/2093376

I did an extensive debugging of the problem and everything points to a bug in the Embedded Controller firmware. I hope Dell decides to fix it. I'm willing to help if Dell's engineers want. It's sad to see Linux being treated as a second class product even though I bought this notebook with Linux.

Meanwhile I made a virtual keyboard to workaround that bug:

https://codeberg.org/Kana/debounce_keyboard

ejn63 · Answer

Run a keyboard diagnostic (F12 at powerup). Does the same fault replicate itself there?

If it does, and whatever seller you purchased from has a warranty, contact them (it's unlikely the system has a Dell warranty, as it's a 2023 model that's either been purchased used or old stock).

desgua · Answer

@ejn63​ thank you so much for your suggestion. My system is still under warranty. I ran a keyboard diagnostic and it says the keyboard is ok. I also contacted Dell's support and because the diagnostic said the keyboard is ok, they didn't provide any solution because they said it isn't a hardware fault (?). I have to figure out where the problem come from, maybe (probably) a firmware bug, or the hybrid cpu, or some kind of interaction with my very light OS.

Inspiron

Random key repeat problem until another key is pressed

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