11-02-2018 03:27 AM
Looks like nobody's answering...
Anyone know how to do something like "mentions" or tagging in another user? We should loop in somebody that's with Lenovo like @someotherguy and see if they could at least get *some* answer about the issue. The silence is deafening!
11-06-2018 07:30 AM
Sorry to have missed this thread until now. I could reproduce this problem on X1 Yoga 2nd, but X1 Yoga 1st and X1 Yoga 3rd work properly even with automatic screen brightness enabled. Since it's the same software (Windows, Vantage, hotkeys, getc) on all 3 models, I guess there may be some misconfiguration on the 2nd-gen that causes this problem. We will investigate it.
11-06-2018 11:42 AM - edited 11-06-2018 11:45 AM
That you very much! This is the only bug that remains on my X1Y2 that I haven't fixed/hacked/coded out. This bug is the only thing that really is holding the 2nd gen back from being the "perfect" care-free machine.
I'm sure I speak for everybody on this topic when I say we look forward to finally getting a resolution on this!
BTW, just to let you know, I've tried every different version of the Intel Sensor Solution driver to be sure it wasn't something in it.
11-06-2018 04:56 PM
I found that by stopping "Sensor Service" in services.msc, then the automatic keyboard backlight will start working. The next step is to find out what components are being loaded by "Sensor Service" to see if we can isolate the one that is causing interference. Note that "Sensor Service" is provided by Microsoft so our ability to debug into it is limited.
11-07-2018 02:59 AM
I had tested that before...and had the WDK debugger hooked to it. The reason the keyboard starts working when SensorService is disabled is that the Auto Screen Brightness is also disabled (no different than if you just turned off the "Change Brightness Automatically When Lighting Changes" in settings. With it off, you get the opposite effect - no auto screen brightness changes despite the keyboard backlight working.
It still seems that something in the message pump is sinking the ambient light sensor messages in the display driver or subsystem. As long as you don't have auto-bright on, the keyboard backlight gets the messages (including disabling the SensorService), but if the display driver handles the message first (and the keyboard backlight makes it to the lowest level), it stops reading the messages.
11-07-2018 05:15 AM
An additional question... does the Intel Serial I/O interface have anything to do with the sensor subsystem on the X1Y2 or is it only for NFC enabled devices? I noticed that there is another SIO update as of yesterday (the same version that Intel released a while ago), but I don't have of the DevIDs for the SIO components. I saw the devices when I first installed this X1Y2, way back and many bios updates ago, but haven't seen them since. Can you check and see what is actually connected to the LPSS/SIO bus on the Y2?
11-11-2018 04:13 PM
Just wanted to check and see if there was any progress getting this fixed up... I was walking in and out of a dark server room today and it reminded me how much it sucks to not have ambient light sensing! Walk in, can't see keyboard and blinded by screen. Turn the keyboard light on and lower brightness. Walk out a bit later and can't see the screen, so turning the brightness up to compensate. After a dozen times or so, it definitely makes you miss the sensor working right!
11-12-2018 07:10 AM
Just wanted to check and see if there was any progress getting this fixed up...
When I installed an old factory preload, based on Win10 14393, everything works. The screen dims and the keyboard backlight turns on when I cover the ambient light sensor. Now we are trying to identify the update that broke this.
11-12-2018 06:28 PM
As I wrote previously, the Win10 1607 (build 14393) factory preload does not have this problem.
Here is results from today's debugging:
- When I ran System Update to install all of the latest drivers from Lenovo, still no problem.
- When I upgraded from 1607 to 1703, still no problem.
- When I upgraded from 1703 to 1709, problem happens
You might know that during OS feature upgrade, Windows backs up current version to C:\Windows.old, and then installs new version.
To fix this problem that happened after 1703 -> 1709 upgrade, I copied the 1703 files like "*sens*.*" from "C:\Windows.old\Windows\System32" to "C:\Windows\System32", overwriting the 1709 files. There are 16 total files like this, such as mfsensorgroup.dll, Sens.dll, SensApi.dll, SensorDataService.exe, etc. All of these are Microsoft-provided files. This makes automatic screen brightness start working again.
So my conclusion is that one or more of these Win10 1709 files causes this problem, and therefore only Microsoft can fix this problem.