Librem 13v2 screen flicker - horizontal lines

My Librem 13v2 was delivered in late December 2017. The screen has always has always flickered.

Every second or two a thin horizontal line flashes on the screen. The position is not constant, could be in the middle, could be in the upper half, near the bottom of the screen, etc. No distortion, just a momentary thin horizontal line.

I have tried various combinations of the two hardware switches, as suggested in another thread, but the horizontal line flicker remains. I have not tried opening up the machine to make sure the connectors are seated, as suggested in another thread, but that’s the next step.

Today I re-installed PureOS from the latest (20180120) ISO, hoping to get an updated driver and see some improvement, but the flicker is still there.

It is very annoying, hard on the eyes, and makes it difficult to use the Librem 13 for extended periods.

Do I have a hardware problem? A driver problem? Can this be fixed, or must I learn to live with it?

Please try this workaround:

It seems a little better with this, but if I open PureBrowser on a page that has a white/light background (e.g. about:preferences#general) I get constant flickering horizontal lines.

@logicprobe could you please attempt to completely power off your laptop (not reboot but power off) after you get a severe flickering issue and see if it goes away when the system powers back on?

@Kyle_Rankin I powered off and rebooted but the flickering horizontal lines are still there. It seems more severe when I have a window with a white background open against the blue jellyfish desktop.

I read this post and just looked to understand what was the workaround about, here is what I found (technical points ahead) :

This trouble is likely to be caused by the i915 DRM driver, there is some open issues about that.

Setting GRUB_CMDLINE_LINUX="i915.enable_rc6=0" in the grub file (/etc/default/grub) will disable the sleep mode of the Graphic chipset, it seems that this can fix the issue on some configuration but not always. Previous link also suggest i915.enable_psr=0 option as a possible solution.

I cannot test any solution but upgrading/ the kernel seems to be a nice solution to get a fixed version of the driver (if any, I couldn’t find much info on that). Advanced user would know how to (can pull from debian testing or even unstable for instance), but for other people I couldn’t find a silver bullet.

Hoping this reply helps (this is not about Librem/PureOS only)

I changed “i915.enable_rc6=0” to “i915.enable_psr=0” and it seems a lot better. Still the occasional thin horizontal line flash, but nothing like before.

Interesting! i was going to try that option instead but when i ran:

sudo systool -m i915 -av

it reported that the option was already set to 0.

I wonder if the problem is temperature related. I hadn’t been using the laptop when I made the change to /etc/default/grub, and I didn’t check with systool before making the change.

I’m glad I read this thread. I had already made the change for i915.enable_rc6=0 but was curious to check whether my Librem 15v3 also showed enable_psr=0. Following @Kyle_Rankin’s hint, I found systool (which is part of the sysfsutils package) and ran the command listed above. I can confirm enable_psr = "0", but enable_rc6 is still set to "1", despite having run the steps in the linked workaround. Powered all the way off and on again, but still enable_rc6="1"

Finally I ran sudo update-grub, then rebooted and now enable_rc6="0". We’ll see if this helps!

For me the solution proposed elsewhere in the forum finally did the trick: Librem 13v2 screen flickers, and solution in Troubleshooting doesn't work
It suggests updating the coreboot bios. After years of living with the flickering, this fixed the issue for me. As there may be other people still struggling with this it might be worth making a reference in the troubleshoot @mladen.

1 Like