Verdin iMX8M Plus - Mallow carrier board and 10 inch DSI display

Hello,

As requested, here is the output of tdx-info:

Software summary
------------------------------------------------------------
Bootloader:               U-Boot
Kernel version:           5.15.129-6.5.0+git.6f8fd49366db #1-TorizonCore SMP PREEMPT Fri Dec 22 11:15:52 UTC 2023
Kernel command line:      root=LABEL=otaroot rootfstype=ext4 quiet logo.nologo vt.global_cursor_default=0 plymouth.ignore-serial-consoles splash fbcon=map:3 ostree=/ostree/boot.1/torizon/fe091cbe7b665ff6d9d5d618cb20c42c90c242fffeaceccf204eacd186b2f597/0
Distro name:              NAME="TorizonCore"
Distro version:           VERSION_ID=6.5.0-build.8
Distro variant:           VARIANT="Docker"
Hostname:                 verdin-imx8mp-15290510
------------------------------------------------------------

Hardware info
------------------------------------------------------------
HW model:                 Toradex Verdin iMX8M Plus on Verdin Development Board
Toradex version:          0063 V1.1B
Serial number:            15290510
Processor arch:           aarch64
------------------------------------------------------------

I am working with an iMX8M PLus Verdin module, plugged in a Mallow carrier board. I tried to get the new 10 inch DSI display working: after enabling the verdin-imx8mp_panel-cap-touch-10inch-dsi_overlay.dtbo overlay, I get a nice image on the display, but the touch interface seems very slow.

For example, on the screen used to create a new Portainer installation or restore from backup, I have to put my finger for 2 to 3 seconds on the display before the cursor reacts to the new input.

What did I do wrong?

Thanks for your help.

Hello @bluespark,

Welcome to the Toradex Community!

We have seen this issue on the Verdin iMX8M Plus when the MIPI-DSI cable is not properly seated.

Can you try to re-seat the cable?
I would recommend to do this first just on the Mallow carrier board.
If the issue continues, then the end on the display itself.

Best Regards,
Bruno

Hello @bruno.tx,

I really hoped it was going to be that simple, unfortunately I carefully re-seated the cable at each end, one at a time, and I can see no improvement.

Do you have another idea?

Kind regards,

Hello @bluespark,

Can you also test the BSP 6 Downstream Reference Multimedia Image?
Depending on your result, it will help us narrow down what may be the issue here.

Best Regards,
Bruno

Ok, I will try as soon as I can and will report the result, thanks for your help.

Kind regards,

Hello @bruno.tx,

I just tried the image you referenced and everything is working fine.

As I did not test a custom application, maybe the problem only occurs on the screen I tested (the one used to create a new Portainer installation or restore from backup).

What’s your opinion?

Hello @bluespark,

Thanks for the information.

We have seen this problem in the past with the Verdin iMX8MM, which was also not solved by re-seating the cable.
From our testing, the Verdin iMX8MP can also experience this issue, but as I mentioned earlier, re-seating the cable has solved the problem.

It is possible a different application would behave differently.
However, from the tests I did with the Verdin iMX8MM, the behavior was very similar in a custom Qt application.

The Torizon OS team is currently investigating the cause of this problem.
Once I have more information, I will send an update to this thread.

Best Regards,
Bruno

Duly noted, let me know if I can help.

Kind regards,

Dear @bruno.tx ,

Do you have any news regarding this issue, and/or do you have an ETA?

Kind regards,

Hello @bluespark,

Unfortunately there are no news about this issue.

I will request for the internal Torizon OS ticket to be published on the Torizon OS issue tracker so that you can follow the progress there.

When that is done or there are further developments, I will send an update here.

Best Regards,
Bruno

The issue has been published to the Torizon OS issue tracker: TorizonCore Issue Tracker

It currently only mentions the Verdin iMX8M Mini because we have not yet been able to reproduce the issue on the Verdin iMX8M Plus.
The behavior we see on the Verdin iMX8M Mini is the exact same you are experiencing on the Verdin iMX8M Plus, so the issue is likely the same.

Best regards,
Bruno

Hello @bluespark,

We may have found the issue.
From some initial testing it appears that increasing the clock rate of the I2C bus used for the touch controller can solve the problem on the Verdin iMX8MM.

I am sending a customized device tree overlay for the DSI display intended to address this.
Can you test if this solution work for you?

To apply the overlay you can follow the steps on Device Tree Overlays on Torizon | Toradex Developer Center

Best Regards,
Bruno

verdin-imx8mp_panel-cap-touch-10inch-dsi_overlay-400khz.dts (1.8 KB)

Hello @bluespark,

Did you have the opportunity to test this modified overlay?

Best Regards,
Bruno

Hi @bruno.tx ,

Unfortunately no, but I’ll try to do it as soon as possible. I’ll keep you posted.

Kind regards,

Dear @bruno.tx ,

To speed up the test on my side, is it possible for you to provide the compiled overlay file, dtbo format?

Thanks in advance.

Kind regards,

Hello @bluespark,

Surely,
The attached device tree overlay has been tested with Torizon OS 6.6.1.
It should only be used for testing, as device tree customizations should be done with TorizonCore Builder.

verdin-imx8mp_panel-cap-touch-10inch-dsi_overlay-400khz.dtbo (3.9 KB)

Best Regards,
Bruno

Dear @bruno.tx,

I did not had time to run some extensive tests, but it seems to be working much better!

I’ll keep you posted as we use it a little bit more.

Thanks for your help.

Kind regards

Hello @bluespark,

Thanks for the update.

Best Regards,
Bruno