After resuming from S3 sleep the ELAN0673:00 04F3:3188 Touchpad in my ThinkPad X1 Carbon Gen9 triggers an IRQ storm. This IRQ storm makes the normal touchpad operations really jumpy. I observed the IRQ storm by watch /proc/interrupts and by adding a print statement to i2c_hid_irq(). (Please note that S3 sleep is not the default on this machine and has to be enabled first in the firmware setup). Attached are various logfiles.
Created attachment 299263 [details] interrupts after resume
Created attachment 299265 [details] lspci -vvnn
Created attachment 299267 [details] ACPI DSDT tale
Created attachment 299269 [details] I2C layout 1
Created attachment 299271 [details] I2C layout 2
Created attachment 299273 [details] dmesg from cooldboot - suspend - resume cycle
According to Lenovo this is a known issue and will require an update of the Touchpad Firmware to be fixed. For the time being S3 sleep is not supported and s2idle should be used instead.
*** Bug 215747 has been marked as a duplicate of this bug. ***
This seems to have been solved with system firmware 1.52.