Touch driver lagging slow

Technical Support
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1

Hello,

We are using riverdi display with ilitek touch driver, but always get the error when press many times very quickly. We are using chromium and cog to do some tests on the user interface.
I have this error with different 2 displays and using 2 different touch drivers, ilitek and mts_mtx.
I can feel the slow performance on the user interface when I get this error.
What can be done to improve this lag?

Riverdy Display: DS_RVT101HVDNWC00-B_Rev.1.0

TorizonOS: Linux verdin-imx8mm-14756371 5.15.129-6.5.0+git.6f8fd49366db #1-TorizonCore SMP PREEMPT Fri Dec 22 11:15:52 UTC 2023 aarch64 aarch64 aarch64 GNU/Linux

Apr 15 15:33:09 verdin-imx8mm-14756371 1dd146263a71[718]: [15:33:09.778] event2 - ilitek_ts: client bug: event processing lagging behind by 36ms, your system is too slow

4

Hello @peterz,

We are aware of an issue with the touchscreen input from the Capacitive Touch Display 10.1" DSI, when paired with the Verdin iMX8MM with Torizon installed. The issue is tracked on our issue tracker: TorizonCore Issue Tracker

However, the known issue does not cause the following issue you reported.
I re-tested this to be sure.

Is the display with the “mts_mxt” touch controller the Capacitive Touch Display 10.1" LVDS?

Is your Torizon OS image customized in any way?

Best Regards,
Bruno

5

Hello @bruno.tx

We are using two displays with the same error. One use ilitek driver and other mts_mxt.
We saw errors independently of the display used.
And the image customization does not affect nothing related to display, only dockers and some services.
We were using chrome and cog to the user interface, now we are testing another UI based on an application instead of browser. I will let you know if the problem persists.

6

Hello @peterz,

Did you have any progress with this problem?

We are investigating a problem with the touch input on the Capacitive Touch Display 10.1" DSI and one of the changes that improved the touch behavior was to increase the I2C bus speed to fast mode.

This can be done by adding a clock-frequency property to the i2c2 node on the display’s device tree overlay:

/* Verdin I2C_2_DSI */
&i2c2 {
...
	clock-frequency = <400000>;
...
}

Best Regards,
Bruno

7

Hello @peterz,

The problem with the Capacitive Touch Display 10.1" DSI was related but not limited to the I2C frequency.
This problem has been fixed and if you are still experiencing touch driver issues I recommend that you test again on one of the latest nightly releases.

Best Regards,
Bruno

8

Hi @bruno.tx,

How soon can we expect a production ready Verdin i.MX8M Plus Yocto release with the changes implemented to fix the 10.1" DSI display touch issues?

Thanks

9

Hello @Sutter99,

The fixes will be available in the next Torizon OS quarterly release, version 6.7.0.
It will be released at the start of next quarter, which means it should be released in the next few weeks.

Best Regards,
Bruno

10

Hi @bruno.tx,

Thank you for replying quickly. I am using Yocto to build images and not using Torizon. How soon will I be able to update my project to include the changes? Might there be patches available?

Thanks

11

Hello @Sutter99,

The release cycle of Torizon OS and the Linux BSP is aligned, therefore BSP 6.7.0 should also be released in the next few weeks with this fix incorporated.
The fix encompasses changes to device trees and device tree overlays, therefore I would recommend that you use one of our images as a base. The latest monthly and nightly releases already have this fix in place.

Best Regards,
Bruno

12

Hi @bruno.tx,

Thank you for that information. I tried both the nightly and monthly images but both fail to find the verdin-imx8mp_panel-cap-touch-10inch-dsi_overlay.dtbo after I modify the overlays.txt file to include that overlay. The boot log error is:

Applying Overlay: verdin-imx8mp_panel-cap-touch-10inch-dsi_overlay.dtbo
3843 bytes read in 1 ms (3.7 MiB/s)
failed on fdt_overlay_apply(): FDT_ERR_NOTFOUND

Thanks

13

Hello @Sutter99,

Can you open another topic on the community so we can support you with this problem?

Best Regards,
Bruno