Bug 202503

Summary: Regression: elan_i2c: touchpad stopped working on device with acpi id ELAN0501
Product: Drivers Reporter: Mirco Tischler (mt-ml)
Component: Input DevicesAssignee: drivers_input-devices
Status: NEW ---    
Severity: normal CC: mt-ml
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: v5.0-rc Tree: Mainline
Regression: Yes

Description Mirco Tischler 2019-02-04 16:07:20 UTC

in version 5.0-rc* the touchpad on my Acer Aspire V-371 stopped working and I get lots of loglines like this:

elan_i2c i2c-ELAN0501:00: invalid report id data (1)

Reverting commit 7db54c89f0b30a101584e09d3729144e6170059d (Input: elan_i2c - add ACPI ID for touchpad in ASUS Aspire F5-573G) resolves this. It seems like the touchpad was handled by hid-multitouch on v4.20 and before as I have these lines in the logs on v4.20 (aquired via dmesg|grep -i elan):

input: ELAN0501:00 04F3:3010 Touchpad as /devices/pci0000:00/INT33C3:00/i2c-0/i2c-ELAN0501:00/0018:04F3:3010.0001/input/input7
hid-multitouch 0018:04F3:3010.0001: input,hidraw0: I2C HID v1.00 Mouse [ELAN0501:00 04F3:3010] on i2c-ELAN0501:00

which switch to this on v5.0:

input: elan_i2c i2c-ELAN0501:00: Elan Touchpad: Module ID: 0x0067, Firmware: 0x0001, Sample: 0x0003, IAP: 0x000a
input: Elan Touchpad as /devices/pci0000:00/INT33C3:00/i2c-0/i2c-ELAN0501:00/input/input6

Is the commit correct? Are there different versions of the touchpad, some requiring elan_i2c and some hid-multitouch?