0

I am trying to install Lubuntu 22.04 on the SD card drive (uSD 64 GB) of a Dell Latitude 7490. I can boot from the USB key, launch the installer, but it always freezes at some point. Sometimes it freezes early, while I am configuring the location, or keyboard, etc, and "at best" the install starts but soon freezes. This is not only the installer that is freezed but the whole PC: the OS is unresponsive and I have no other choice than shutting it down by pressing the power button.

I have tried with 2 different USB keys (old ones, but still working ones), 2 different USB ports, and I have even tried with the 20.04 installer. In all cases it freezes...

What could be wrong?

EDIT:

  • as all Lubuntu installation trials were ending with a freeze at some point, I finally tried installing Xubuntu 22.04. It worked.
  • I was quite happy, could boot on as newly installer SD card... and it freezed while I was applying the updates. I could no longer boot on the card, the filesystem was apparently corrupted.
  • I reinstalled Xubuntu from scratch, booted again on the card, played a bit with the applications, browsed the web... and as soon as I launched the installation of the updates, it freezed again.

Notes:

  • during the boot on the SD card I can see various error messages related to ACPI, or to the filesystem of the SD card (see below):
  • dmesg | grep mmc reports the following error about the SD card every 5 sec. or so: mmc0: cannot verify signal voltage switch

enter image description here

EDIT

It has apparently nothing to do with the SD card: I could install Xubuntu 22.04 on an external drive (SSD), I can boot on it, but everything freezes after 1 or 2 mn. Hypothesis:

  • this PC is not fully compatible with Linux (at least the *ubuntu distributions)
  • it has a hardware problem (this is an office PC with Windows 10 installed on the internal drive, and I have also experienced some freezes with Windows, although much less frequent (say 3/4 times during one year)
PierU
  • 111

1 Answers1

1

Diagnostic

It turns out that the kernels >4.19 are the culprits. The problem is related to the iGPU (Intel core i5-8250U with UHD 620 on the Latitude 7490) and the "Panel Self Refresh" feature that is enabled by default on kernels >4.19.

https://medium.com/@natchanan.th/linux-5-x-random-kernel-panic-workaround-4e063e4d34a7

https://www.reddit.com/r/linuxquestions/comments/k4imsd/freeze_on_kernels_419_because_of_i915_dell/

It seems that some other Dell models are concerned, but it's not clear if all of them have a UHD 620 iGPU, or if models of other brands are concerned too...

Solutions

I installed Xubuntu 18.04 LTS (kernel 4.15) and had no more freeze.

The solution with more recent kernels is to disable the PSR feature, by creating this configuration file:

sudo echo "options i915 enable_psr=0" > /etc/modprobe.d/i915.conf

In practice I created the file under Xubuntu 18.04, and then I upgraded to 20.04, and eventually 22.04. If one wants to directly install a recent version, it seems that the option has to be passed to Grub at boot time at least to have a session that doesn't freeze (and then one can create the configuration file)

More troubleshooting

The above solution does actually not completely eliminate the freezes. They can still happen when the screen wakes up after being put to sleep.

To avoid that, I have found that in Settings > Power Manager > Display, it was enough to set "Blank after" on "Never". Strangely, it is possible to use "Put to sleep after" and/or "Switch off after", without having freezes. Also, putting the OS to sleep (suspend) doesn't result in a freeze after wake-up.

PierU
  • 111