Touchpad not longer detected

So, since updating to Linux Kernel 5.4 and up, my Touchpad on my Lenovo Ideapad 720s15IKB is not longer responding. dmesg | grep touch dont show any longer the Device, like it is disappered from the System.

Due to the fact that i need the Touchpad working, i am now running it on the 5.3.7 Kernel for now, but i could need help to fix it. Using the Gnome Firmware Tool i could see it is detected as some “Synaptics”-Device, but also there arent any Firmware-Updates.

So, i hope someone with more knowledge of Kernel and driver than me can help me so i can get the Touchpad on the newer versions running.

No knowledge. Try this link:
The Wiki: Troubleshooting. Look for Touchpad not detected at all section.

The Kernel Parameters listed there dont solved it.

I have checked also the /proc/bus/input/devices file, which also dont list the Touchpad in the current Kernel, so i expect somthing in the drivers or like this, but like I said, I dont know how or where the problem lies.

Did your tried to use grep -i touch (case insensitive)?

Used it, but it is the same case as before:

On the 5.3.7 Kernel it shows the Touchpad, but not on the 5.4 Kernel, so it has definitly to do something with a change in the Kernel.

When using 5.3.7, the Touchpad is the following:

$ dmesg | grep touch
[    4.945518] hid-multitouch 0018:06CB:7F8D.0001: input,hidraw0: I2C HID v1.00 Mouse [MSFT0001:00 06CB:7F8D] on i2c-MSFT0001:00

$ cat /proc/bus/input/devices | grep -i touch
N: Name="MSFT0001:00 06CB:7F8D Touchpad"

: ( https://www.kernel.org/doc/html/v4.10/admin-guide/reporting-bugs.html ?