E14 hardware tweaks

TODO: miscellaneous hardware notes for a conscientious editor to organize

linux 5.6.13 debian sid xorg 1.20.8

CPU

• horrible lenovo throttling DOES affect the Lenovo E14 in linux
  • https://www.notebookcheck.net/Lenovo-admits-ThinkPad-CPU-throttling-problem-when-running-Linux-fix-in-development.435549.0.html
• erpalma's workaround (lenovo_fix / throttled) works adequately
  • https://github.com/erpalma/throttled
  • (i personally set the trip temp to 97 degrees, and set battery to the same as AC, and i see good performance AND battery life)

WIFI

RTL8822-CE

• this is what it comes with
• works just fine ootb on linux 5.6.13
• observing wifi speeds 22MiB/s (against RT-AC68U running ddwrt)

Intel Wireless AX201

• works, but ONLY on bios 1.11+
  • not detected in lspci OR lshw running BIOS 1.09
• requires a kernel 5.2 or higher, and doesnt work on SOME 5.4 and 5.6 kernels
  • works on 5.6.13 kernel, BUT loads iwlwifi-QuZ-a0-hr-b0-48.ucode and lshw prints "Wireless-AC 9462" but it seems
  • observing wifi speeds around 70MiB/s (against RT-AC68U running ddwrt)

Graphics

• works fine on linux 5.6.13
  • 1080p media playback is smooth
  • cuphead on steam proton runs smooth at 1920x1080
• HDMI works
  • 4k media is smooth
  • 5.1 channel audio works correctly with pulse (hdmi profile is hdmi2, hdmi1 is usb-c)
• BUG: observed occasional HORRIBLE flickering
  • every once in awhile, screen would start flickering to black every second or two
  • once it started, it would keep going like that until reboot
  • dmesg: drm:intel_cpu_fifo_underrun_irq_handler
  • i915.enable_rc6=0 on the linux cmdline fixed it, at least for the past 12 days
• seems to require a 5.0+ kernel
  • hd graphics wouldnt load at all on a late 4.x kernel
  • cpu rendering worked fine, at 1280x720, but was ugly

NVME

Sabrent 4TB Rocket NVME M.2

• works BEAUTIFULLY, 3634MB/s real world read speed, 3122MB/s real world write speed

SATA

Samsung 860 EVO 2TB 2.5" SATA 7mm

• works great, 568MB/s read, 529MB/s write

LCD

IPS 250 nits

• its ok

LEDs

• Thinkpad (i) LED is unknown_led2 in thinkpad_acpi
• power, green:batt and orange:batt, mute, and micmute all work

Fan

• auto mode actually works well (fan is off most of the time, and quiet under moderate load, and loud as hell under heavy load)
• thinkpad_acpi 0, 1, 2, and 3 all completely turn off the fan
• thinkpad_acpi 4, 5, 6, and 7 all turn the fan to max