Tapping on the touchpad stopped working in gentoo-sources-6.6.58-r1. I see the following in dmesg output; the first line was not there in previous kernel versions: [ 2.129282] hid-multitouch 0018:27C6:01E0.0001: The byte is not expected for fixing the report descriptor. It's possible that the touchpad firmware is not suitable for applying the fix. got: 9 [ 2.137479] input: GXTP5140:00 27C6:01E0 as /devices/platform/AMDI0010:00/i2c-0/i2c-GXTP5140:00/0018:27C6:01E0.0001/input/input10 [ 2.137680] input: GXTP5140:00 27C6:01E0 as /devices/platform/AMDI0010:00/i2c-0/i2c-GXTP5140:00/0018:27C6:01E0.0001/input/input11 [ 2.137921] hid-multitouch 0018:27C6:01E0.0001: input,hidraw0: I2C HID v1.00 Mouse [GXTP5140:00 27C6:01E0] on i2c-GXTP5140:00 Hardware is Lenovo ThinkPad L15 Gen 4: https://linux-hardware.org/?probe=1b28fd0c04 The problem did not occur with the previous stable version 6.6.52.
Created attachment 907741 [details, diff] Patch that fixes the problem here Reverting this hunk from 1056_linux-6.6.57.patch fixes (or works around?) the problem here.
Upstream commit that introduced the problem is here: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/hid/hid-multitouch.c?id=251efae73bd46b097deec4f9986d926813aed744
