Lenovo C940 Flickering/Distortion with HWA enabled in applications win10 (2004+)

[Bertil78]

Hi

In desperation i (and many others) owners of the Lenovo C940 is looking for a solution here.

Lenovo and Microsoft is deadsilent on this matter...

After Windows 10 updated to version 2004 and 20H1/20H2 we have noticed major issues with hardware acceleration causing flickering/black screens. and we have tracked it down to hardware acceleration (software). Versions of windows from 1909 and below is working as it should. All drivers and firmwares is up to date.

please use some mins to look at these threads where myself and others have narrowed down the issues, and maybe this something intel can fix in drivers to come...

reddit:

https://www.reddit.com/r/Lenovo/comments/iragjx/c940_flickeringdistortion_with_hwa_enabled_in/

lenovo community:

https://forums.lenovo.com/t5/Lenovo-Yoga-Series-Notebooks/Lenovo-Yoga-C940-screen-glitches-flickering-flashing/m-p/5044566?page=1

https://forums.lenovo.com/t5/Windows-10/Lenovo-devices-tested-for-Windows-10-version-2004-May-2020/m-p/5019631?page=2

Thanks in advance

Bertil

[Maria_R_Intel]

Hello Bertil78,

Thank you for posting on the Intel* Community.

To better assist you, please provide us with the below details:

Please run the following tool in Windows* and attach the report generated. 

Intel® System Support Utility (Intel® SSU) 

• Intel® SSU Download
• Open the application and click on "Scan" to see the system and device information. By default, Intel® SSU will take you to the "Summary View". 
• Click on the menu where it says "Summary" to change to "Detailed View". 
• To save your scan, click on "Next", then "Save". 

Provide the Intel* Graphics Command Center report:

>Go to the Intel Graphics Command Center

>Support

>System Diagnostic

>Generate report.

>Attach the report file.

• Please, attach pictures and videos to this thread, so we can have the proper documentation here.
• Just to confirm, when you disable the hardware acceleration on the apps the flickering and issues stop?

Best regards,

Maria R.

Intel Customer Support Technician

[Mohammad]

There are lot of people complaining about this issue. I send my new C940 to Lenovo repair center two times. They changed the display, display cable and hinge which did not fix the issue. Later I found almost all user who upgraded their laptop to Windows 2004 and uses Hardware Acceleration are having the same problem.

I have attached a video of the problem here. Hope you will release a fix soon.

//Mohammad

[Maria_R_Intel]

Hello Bertil78,

Were you able to check the previous post? 

Let me know if you need more assistance. 

Best regards, 

Maria R.  

Intel Customer Support Technician 

[Bertil78]

hi

to reproduce this software bug i have to upgrade to an OS (windows 10 2004+) update that will once again give me trouble (and others). this is not an option, my machine is working great atm under windows 10 1909 (and below).

And yes, the problem/bug goes away if hardware acceleration is disabled in the app(s). chrome/edge, office, and the list goes on.

As stated and in the links provided to lenovo and reddit site, the problem is the update to windows 10 2004 and forward. it does something/changes to the gfx/gpu on the machines. (not just the c940). it still remains on the latest 20H20 update. so maybe it breaks something in the intel drivers?

I (and others) have testet the whole spectre of intel drivers without luck.

i have atteched SSU info of my current working setup

[Maria_R_Intel]

Hello,

Thank you very much for the information provided.

In this case, you have to understand that there are two different types of drivers, generics provided by Intel and Equipment Manufacturer drivers, that are customized to work with each specific system.

We highly recommend using the drivers that are provided by the system manufacturer or via Windows Update to eliminate the potential impact caused by loading non-customized drivers (Intel's generic drivers that were not tested on your specific system). The system manufacturers regularly customize Intel generic drivers to meet the needs of their specific system design. In such cases, the use of the Intel generic driver update is not recommended.

I searched on Lenovo's website but they do not have the graphics drivers available at the moment. So I think is worth it to try the latest generic driver that Intel* releases, version 27.20.100.8935.

Please follow the steps for a clean installation:

Clean installation steps:

1. Download the latest Graphics Driver 27.20.100.8935 
2. Disconnect from the Internet so no new drivers are automatically installed by Windows Update. 
3. Uninstall the driver and the Intel Graphics Driver from Apps and Features.
4. Restart the computer. 
5. Go to the Device Manager > Video Adapters and check if the controller is listed as 'Microsoft Basic Display Adapter'. If the adapter continues to be listed as ‘Intel HD Graphics’ or similar, and no other Intel Graphics driver is listed under 'Programs and Features' for removal, then it means Windows has switched to a previously installed Legacy driver. At this point, we can remove Legacy drivers from Device Manager: 
   5.1. Right-click on 'Intel HD Graphics' or similar, and select 'Uninstall Device'
   5.2. In the pop-up window make sure 'Delete the driver software for this device' is checked. 
   5.3. Click on 'Uninstall'. 
   5.4. Restart. (Repeat steps 5.1 through 5.4 until the device gets listed as 'Microsoft Basic Display Adapter') Note: Repeat this process until you get the Microsoft Basic Display Adapter.
6. Install the previously downloaded Graphics Driver
7. Reconnect to the Internet and reboot your PC.

If the generic driver also fails, this behavior should be reported directly to Lenovo again, since this issue has not been reported by other users using different systems, and Lenovo should provide custom drivers that they tested and validated for each specific system.

Best regards, 

Maria R.  

Intel Customer Support Technician 

[Bertil78]

hi Maria

been there , done that. all troubleshooting and options with old, new drivers testet. also from manufacturer (lenovo). Lenovo says even that its testet with windows 10 2004 update.

to be spesific about windows 10:

KB4566782 (one of the updates for 2004)

https://support.microsoft.com/en-us/help/4566782/windows-10-update-kb4566782

update to Windows Graphics, Microsoft Graphics Component etc.

this might be the problem and its not fixed in the latest windows 10 20H2 (october) update.

What about Hardware-accelerated GPU scheduling ?

Windows added this in some of their latest updates (WDDM2.7). and this is not (yet) supported by intel?

Just throwing some bones out.

And regarding reporting this to lenovo,...i have bigger chance to get a call from the national lottery. still no reply since i and others reported this. also reported to microsoft without any feedback.

Bertil

[Maria_R_Intel]

Hello Bertil78,

Thank you for your response.

Yes, it is true, according to our public article Is Hardware-Accelerated GPU Scheduling Supported by Intel® Integrated Graphics? the response is: "This feature is currently not supported by the latest Intel DCH drivers."

But please, let me check this internally and I will provide you with more information as soon as possible.

Best regards, 

Maria R.  

Intel Customer Support Technician 

[Mohammad]

Hi Maria,

Is there any hope to get a fix soon?

[Maria_R_Intel]

Hello Mohammad,

We are working to verify if the behavior is due to the Intel components, in the meantime, we cannot confirm if we will provide a fix but we are working hard to verify all the information and do our best to help the customers with this.

Thank you for your understanding.

Best regards,

Maria R.

Intel Customer Support Technician

[Loccy]

Hi all,

I don't have anything profound to say here; I am mainly just bouncing this to confirm that I also have the issue and also to thank Maria and Intel for at least RESPONDING to customers' queries about it. Lenovo and Microsoft have effected a stony silence up until now. Kudos to Intel for accepting that there is at least an issue to investigate and looking into it.

Help us Intel Wan Kenobi, you're our only hope 🙂

[Maria_R_Intel]

Hi @Loccy,

Thank you for your comment! We are doing our best and trying to replicate this in our labs. We really appreciate your post.

We will be posting some updates as soon as possible.

May the force be with us! 🙂

Best regards, 

Maria R.  

Intel Customer Support Technician 

[Maria_R_Intel]

Hello all,

We tested this in our LABS using our drivers to discard corruption on it.

We want to confirm that we were unable to replicate the issue, we tried different scenarios and the flickering/distortion was never present.

First, we want to confirm that Hardware-accelerated GPU scheduling is not supported on our latest DCH drivers. Intel is working on incorporating this feature but we cannot comment on the estimated time for implementation nor which platforms will support it.

As for the flickering issue, Intel needs users to report this directly to Lenovo as it is happening mainly on the Yoga C940 and thus Lenovo needs to debug the issue using the same hardware. If Lenovo finds out the issue is coming from Intel driver's code then Lenovo will work with Intel to address it. Another important data point to consider when reporting this to Lenovo: Is the flickering occurring when connecting an external display as well?

Interesting enough after reading the replies on the Reddit thread, there are users that report the issue also occurs when hardware acceleration is still turned off and other users that have 2 C940's with the same specs, both have the same programs and updates, but it has only happened on one of them so far (this might point to a hardware customization issue) thus it should be reported to Lenovo.

Best regards, 

Maria R.  

Intel Customer Support Technician 

[AskN0More]

Hello Maria

First of all, I want to thank you for your efforts to help people who lives this unfortunate issue.

I wanted to join this topic as i am in the same ship as many of c940 customers. Its very unfortunate that, i was so happy when i bought this device as a valuable piece of Intel-Lenovo work but now dont know what to do...

I want to clarify what i have tested so far in last 1.5 months about this issue.

1: No matter what driver I use, I live this issue as long as i am in the latest version (2004) of Windows OS with my MS Edge, Chrome or MS Office has hardware accerelation feature is turned on.

2: I tested for 1 week extensively (6-7 hours a day) to see if that happens when "Hardware Accerelation feature" is off in these softwares and this problem never happened when i closed this feature in MS Edge, Chrome and MS Office.

3: I got my device back to 1909 version of Windows and again the issue never happened.

4: I got the device back to latest version of Windows again and unfortunately, any of these drivers can not stop this issue happening.

5: This issue has no routine. Sometimes it  happens 2-3 times in row in 5 minutes. Sometimes 4 times in all day.

All these tests make me think that this is about driver, software, or some kind of incompatibility issue between the device and the latest version of Windows. (cant be sure about hardware failure.)

About this matter, you are the only one who we can hear from. I also reported this matter to Lenovo twice. No any signals from them...

[AskN0More]

Sorry, my latest windows version must be Windows 10 20H2 (Version 2009). Latest one. I mistyped.

[Bertil78]

Lenovo Norway actually responded back to me......

Quick translation from norwegian:

Hi Bertil, unfortunately this error has probably occurred after a windows update, and it is not something we can fix since it is windows and and the respective manufacturers that release updates for monitor drivers such as intel, nvidia, AMD etc and not us.

We have no control over this and we do not release these updates if it turns out to be software that creates the problem. So recommend trying an update / reinstallation of monitor driver, bios update or wait till a new windows update comes out or run factory reset on device.

I also see that there are many who have responded to the forum post and, as well, they have been very helpful.

We can also take a closer look at the case, then it would have been nice if you checked what kind of bios version is installed, this can be checked in lenovo vantage. Sometimes we have to send this out manually.

Sincerely Cas Lenovo customer service

[Bertil78]

abit more from conversation:

edit: (conversation)

Hi
 
The bios version I am running is AUCN57WW

---

Hi, then you have the latest bios version, have you tried upgrading device through lenovo vantage? 
This is previously installed on our machines usually. If not, then it is recommended mentioned in the previous email, 
because this problem unfortunately indicates that a windows update has gone wrong. Want a guide to factory reset?
Sincerely

Cas

---

Everything is up to date.

Have rolled back to windows 10 1909.

Have also tested with the latest bios and newer drivers (and older) on windows 10 2004/2009 (20h1 / 20h2). and the problem reappears.
Drivers are also newer than on Lenovo's website, usually lagging behind on the website. And yes, drivers from lenovo is tested first.

Maybe you can try to reproduce the problem yourself and inform microsoft / intel?
Intel does not have these models and can not reproduce these problems.
Microsoft do not respond.

Maybe Lenovo can report this issue with Windows 10 2004+?
It says that windows 10 2004 has been tested and trusted for C940 on the website and on the forum / community.

Absolutely tragic that you can not run the latest version of windows on this premium device we have paid so much for.
Lenovo should push itself a bit around pressing the right channels  to get some feet going. Very quiet around this from you.

[Sebastian_M_Intel]

Hello all, 

Thank you for the update provided on the thread. 

As previously mentioned, we did try doing a replication in our labs with a different system configuration and we did not see the issue. As this problem is related to the Lenovo* laptops only, that is the reason why we recommend you to work with the Original Equipment Manufacturer (OEM) for further support. Feel free to make a reference to this thread if necessary. 

Please remember that if Lenovo* is able to find out the issue is coming from Intel driver's code then they will work with Intel to address it.  

Regards, 

Sebastian M  

Intel Customer Support Technician  

[Bertil78]

Response By E-mail (Cas) (01/12/2020 12.13 PM)

Hi, we have received very few cases regarding this reported to us and unfortunately do not get to reproduce this either.

We also have no portal to other manufacturers through tech support. So unfortunately there is little we can do but wait for a new windows update or contact microsoft support if they knowif there is a solution to this directly through them that we have not heard about.

But if they know this internally (those above us), then they are probably working on the case.But since it turns out to be an update in the end, it is microsoft that must solve the problemas long as it does not turn out to be hardware defective.

But so far it has not indicated that this is the case.

Sincerely Cas

o well..............

[Maria_R_Intel]

Hello all,

Unfortunately, Intel has tried reproducing the issue using the same generic drivers but we haven't seen it, suggesting it is triggered by either OEM customization (per example: OEM proprietary software that is conflicting with the feature or specific hardware implementation).

If Lenovo doesn't reproduce the issue, then it is up to Microsoft since it is their feature.

Since we do not have more steps to provide, we will proceed to close this thread.

Thank you for your understanding. Have a nice day!

Best regards,

Maria R.

Intel Customer Support Technician