07-07-2018 04:00 AM
My Lenovo X1 Carbon with Ubuntu release 17.10 has started blinking two weeks ago. Once every five minutes, something that looks like an other (almost transparent) screen appears for a very small fraction of time. Immediately after this happens, the screen blinks (gets black) , also in this case for a tiny fraction of time. In some cases, before the screen blinks it seems to shift from left to right. Sometimes, it starts doing this thing more frequently (about once every 3 seconds for one or two minutes). I can not relate this to any of my actions.
I can't find a better way to describe the problem, hope this gives an idea. Has anyone any suggestion for at least trying to solve this problem? Thank you in advance.
07-07-2018 07:33 AM
1. Does the screen blinking occur during bootup or in the BIOS?
2. Does the screen blinking occur when you are using it with Windows?
3. Does the screen blinking occur with an older version of Ubuntu?
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07-08-2018 01:33 AM
1. The screen is NOT blinking during BIOS or bootup. It starts as soon as the bootup terminates.
2. I don't have Windows, only ubuntu.
3. I have upgraded ubuntu to the newest version:
>lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 18.04 LTS Release: 18.04 Codename: bionic
The problem has not been solved.
07-10-2018 09:26 PM
This might be due to the new panel self refresh (psr) power savings feature enabled in kernel 4.17. To see if it is active on your machine, issue this:
sudo cat /sys/kernel/debug/dri/0/i915_edp_psr_status
If you see yes beside enabled, then it is being used to save power and may be causing your issue.
You can disable it by passing along this kernel parameter in grub: i915.enable_psr=0, then see if it solves the problem.
Psr saves me about .5W (more than 10% savings at idle) with no negative side effects (in Fedora 28) on my X1Y3.
07-11-2018 12:17 AM - edited 07-11-2018 12:28 AM
no, it does not seem to be enabled. This is what I get:
Sink_Support: yes Source_OK: no Enabled: no Active: no Busy frontbuffer bits: 0x000 Re-enable work scheduled: no Main link in standby mode: no HW Enabled & Active bit: no Performance_Counter: 0
07-11-2018 12:27 AM
Maybe this can be helpful, If I run:
lshw -C video
*-display description: VGA compatible controller product: Haswell-ULT Integrated Graphics Controller vendor: Intel Corporation physical id: 2 bus info: pci@0000:00:02.0 version: 0b width: 64 bits clock: 33MHz capabilities: vga_controller bus_master cap_list rom configuration: driver=i915 latency=0 resources: irq:43 memory:f0000000-f03fffff memory:e0000000-efffffff ioport:3000(size=64) memory:c0000-dffff
07-12-2018 08:29 AM
After noticing that the blinking was "position dependent" I realized that it increased when I was at some special same points, while it decreased in some other areas. It turns out that the areas where this blinking occurs frequently are areas where there are a lot of different wifis, and every time my computer tries to connect to a wifi, it starts blinking. In airplane mode, the blinking stops, so it is definitely happening whenever my computer tries to connect to a wifi.