Mouse/touchscreen polling affects CPU load?

[ad...@dbanet.org]

Hello,

We are trying to run a web app on BBB via a browser in kiosk mode, and have ran into a significant CPU load (20% with plain xterm on X11) when using touchscreen or mouse. Situation gets worse if we actually run a web browser.

Then we have found using different mice produced different CPU loads, so we ran evhz which showed 133 Hz for one mouse, 1000 Hz for another, and 500-1000 Hz for touchscreen.

For the mice, usbhid.mousepoll option configures the polling interval used by the usbhid driver/kernel module, and we had successfully set the intervals for USB mice.

However, for the TI touchscreen driver, no such configurable option has been found.

Is there any way to lower the polling interval, perhaps with a compile time option?

With best regards,
Boris.

[Robert Nelson]

You could try monkey-ing with the clock dividers:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/mfd/ti_am335x_tscadc.c#n213

Regards

--
Robert Nelson
https://rcn-ee.com/