Re: Elantech touchpad not working on mainline kernels

[Hans Schultz <hans.schultz@webspeed.dk>]

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:
> > On Wed, Jul 21, 2021 at 11:09 AM Hans Schultz <
> > hans.schultz@webspeed.dk> wrote:
> > > 
> > > On Wed, 2021-07-21 at 10:48 -0700, Dmitry Torokhov wrote:
> > > > Hi Hans,
> > > > 
> > > > On Sun, May 30, 2021 at 2:12 AM Hans Schultz <
> > > > hans.schultz@webspeed.dk> wrote:
> > > > > 
> > > > > 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.
> > 
> > > 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