Re: Elantech touchpad not working on mainline kernels

On Wed, 2021-07-21 at 21:31 +0200, Hans Schultz wrote:

Hi Dmitry,

On Wed, 2021-07-21 at 12:14 -0700, Dmitry Torokhov wrote:

quoted

On Wed, Jul 21, 2021 at 11:09 AM Hans Schultz <
hans.schultz@webspeed.dk> wrote:

quoted

On Wed, 2021-07-21 at 10:48 -0700, Dmitry Torokhov wrote:

quoted

Hi Hans,

On Sun, May 30, 2021 at 2:12 AM Hans Schultz <
hans.schultz@webspeed.dk> wrote:

quoted

Hello,
I have a problem getting my Elantech touchpad to work with
the
mainline
kernels, and I need some assistance with the code to resolve
the
problem.
The kernels that have tried are 5.9.11 and 5.11.11.

With boot parameters i8042.notimeout i8042.nomux, the
touchpad is
detected but does not work. There is absolutely no response
from
it
with any hid modules loaded.

It is reported and seen working on a Lubuntu distro (bionic
kernel)
when inserting the i2c_hid module. The insertion of the
i2c_hid
module
pulls in the hid_multitouch module when it works, no boot
parameters
necessary.
In the case where it does not work, insering the i2c_hid
module
does
not pull in the hid_multitouch module.

I have the bionic kernel code, but I have not as of yet been
able
to
detect what makes it work in contrast to the kernel.org
kernels.

This I think should lead to a kernel patch.

There is not much to go on with. What is the hardware, your
kernel
.config, dmesg from unsuccessful boot? If you have logs from
the
working kernel that would help too.

Thanks.

The best info I have on the hardware is from Xorg log with the
working
Lubuntu kernel:
[ 130.980] (II) Loading
/usr/lib/xorg/modules/input/synaptics_drv.so
[ 130.982] (II) Module synaptics: vendor="X.Org Foundation"
[ 130.982] (II) Using input driver 'synaptics' for '0X45 0X4C
0X41
0:00
04F3:308C Touchpad'

I might be able to get the kernel messages when inserting the
working
module, but I think it will not tell much more.

OK, if you say so. Then the only suggestion I have is to verify
that
your kernel config enables all necessary options for your hardware.
I'd double check if you have Designware I2C controller enabled,
ACPI
LPSS, etc.

quoted

To me it is clearly a code issue as the working kernel pulls in
hid_multitouch when inserting i2c_hid, while the non-working does
not.

All kernels I have tried up to now from kernel.org do not work.
The
latest being 5.13.4.

Thanks.

I have a thread with all the dmesg info for both the working and non-
working cases here :
https://gitlab.freedesktop.org/libinput/libinput/-/issues/544

Benjamin has also asked for the acpidump info, which is there. (funny
as the responses to my problem come at the same time after a long
time.
:-) )

I will check my .config...

Thanks,
Hans

Here are my I2C kernel settings. I only added what I could see as with
Intel hw, so no Designware!

#
# I2C support
#
CONFIG_I2C=y
CONFIG_ACPI_I2C_OPREGION=y
CONFIG_I2C_BOARDINFO=y
CONFIG_I2C_COMPAT=y
CONFIG_I2C_CHARDEV=y
CONFIG_I2C_MUX=m

#
# Multiplexer I2C Chip support
#
CONFIG_I2C_MUX_GPIO=m
CONFIG_I2C_MUX_LTC4306=m
CONFIG_I2C_MUX_PCA9541=m
CONFIG_I2C_MUX_PCA954x=m
CONFIG_I2C_MUX_REG=m
CONFIG_I2C_MUX_MLXCPLD=m
# end of Multiplexer I2C Chip support

CONFIG_I2C_HELPER_AUTO=y
CONFIG_I2C_SMBUS=m
CONFIG_I2C_ALGOBIT=y

#
# I2C Hardware Bus support
#

#
# PC SMBus host controller drivers
#
# CONFIG_I2C_ALI1535 is not set
# CONFIG_I2C_ALI1563 is not set
# CONFIG_I2C_ALI15X3 is not set
# CONFIG_I2C_AMD756 is not set
# CONFIG_I2C_AMD8111 is not set
# CONFIG_I2C_AMD_MP2 is not set
CONFIG_I2C_I801=m
CONFIG_I2C_ISCH=m
CONFIG_I2C_ISMT=m
CONFIG_I2C_PIIX4=m
# CONFIG_I2C_NFORCE2 is not set
# CONFIG_I2C_NVIDIA_GPU is not set
# CONFIG_I2C_SIS5595 is not set
# CONFIG_I2C_SIS630 is not set
# CONFIG_I2C_SIS96X is not set
# CONFIG_I2C_VIA is not set
# CONFIG_I2C_VIAPRO is not set

#
# ACPI drivers
#
# CONFIG_I2C_SCMI is not set

#
# I2C system bus drivers (mostly embedded / system-on-chip)
#
# CONFIG_I2C_CBUS_GPIO is not set
# CONFIG_I2C_DESIGNWARE_PLATFORM is not set
# CONFIG_I2C_DESIGNWARE_PCI is not set
# CONFIG_I2C_EMEV2 is not set
# CONFIG_I2C_GPIO is not set
# CONFIG_I2C_OCORES is not set
# CONFIG_I2C_PCA_PLATFORM is not set
# CONFIG_I2C_SIMTEC is not set
# CONFIG_I2C_XILINX is not set

#
# External I2C/SMBus adapter drivers
#
# CONFIG_I2C_DIOLAN_U2C is not set
# CONFIG_I2C_CP2615 is not set
# CONFIG_I2C_ROBOTFUZZ_OSIF is not set
# CONFIG_I2C_TAOS_EVM is not set
# CONFIG_I2C_TINY_USB is not set

#
# Other I2C/SMBus bus drivers
#
# CONFIG_I2C_MLXCPLD is not set
# end of I2C Hardware Bus support

# CONFIG_I2C_STUB is not set
# CONFIG_I2C_SLAVE is not set
# CONFIG_I2C_DEBUG_CORE is not set
# CONFIG_I2C_DEBUG_ALGO is not set
# CONFIG_I2C_DEBUG_BUS is not set
# end of I2C support