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.