Re: [REGRESSION] ThinkPad L15 Gen 4 touchpad no longer works

["Ulrich Müller" <ulm@gentoo.org>]

>>>>> On Sat, 09 Nov 2024, Linux regression tracking (Thorsten Leemhuis) wrote:

> On 03.11.24 09:24, Ulrich Müller wrote:
>> After upgrading from 6.6.52 to 6.6.58, tapping on the touchpad stopped
>> working. The problem is still present in 6.6.59.
>> 
>> I see the following in dmesg output; the first line was not there
>> previously:
>> 
>> [    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 a Lenovo ThinkPad L15 Gen 4.
>> 
>> The problem goes away when reverting this commit:
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/hid/hid-multitouch.c?id=251efae73bd46b097deec4f9986d926813aed744

> Thx for the report. Is this a 6.6.y specific thing, or does it happen
> with 6.12-rc6 or later as well?  And if it does: does the revert fix it
> there, too?

It still happens with 6.12-rc6, and the revert fixes it.