PROBLEM: Elan touchpad regression on Kernel 5.0.10

[Outvi V]

Hello,

[1.] One line summary of the problem: Elan touchpad regression on Kernel 5.0.10

[2.] Full description of the problem/report:
  Elan touchpad does not work on 5.0.10 while working on 5.0.9

[3.] Keywords: elan_i2c_core elan i2c touchpad 5.0.10

[4.] Kernel information
[4.1.] Kernel version:
  Linux version 5.0.10-arch1-1-ARCH (builduser@heftig-2592) (gcc version 8.3.0 (GCC)) #1 SMP PREEMPT Sat Apr 27 20:06:45 UTC 2019
[4.2.] Kernel .config file:
  I'm not sure, but I think it may be referring to
  https://git.archlinux.org/svntogit/packages.git/tree/trunk/config?h=packages/linux
[5.] Most recent kernel version which did not have the bug: 5.0.9

[6.] Output of Oops.. message (if applicable) with symbolic information
     resolved (Not appliable)
[7.] A small shell script or example program which triggers the
     problem: (Not appliable)

[8.] Environment
[8.1.] Software (add the output of the ver_linux script here)
  
Linux sheltty 5.0.10-arch1-1-ARCH #1 SMP PREEMPT Sat Apr 27 20:06:45 UTC 2019 x86_64 GNU/Linux

GNU C                   8.3.0
GNU Make                4.2.1
Binutils                2.32
Util-linux              2.33.2
Mount                   2.33.2
Module-init-tools       26
E2fsprogs               1.45.0
Jfsutils                1.1.15
Reiserfsprogs           3.6.27
Xfsprogs                4.20.0
PPP                     2.4.7
Linux C Library         2.29
Dynamic linker (ldd)    2.29
Linux C++ Library       6.0.25
Procps                  3.3.15
Kbd                     2.0.4
Console-tools           2.0.4
Sh-utils                8.31
Udev                    242
Modules Loaded          8021q 8250_dw ac ac97_bus acpi_thermal_rel aesni_intel aes_x86_64 agpgart ahci arc4 atkbd battery bbswitch bluetooth btbcm btintel btrtl btusb cfg80211 coretemp crc16 crc32c_generic crc32c_intel crc32_pclmul crct10dif_pclmul cryptd crypto_simd crypto_user drm drm_kms_helper ecdh_generic elan_i2c evdev ext4 fat fb_sys_fops fscrypto garp ghash_clmulni_intel glue_helper hid hid_generic i2c_algo_bit i2c_hid i2c_i801 i8042 i915 idma64 input_leds int3400_thermal int3403_thermal int340x_thermal_zone intel_cstate intel_gtt intel_lpss intel_lpss_pci intel_pch_thermal intel_powerclamp intel_rapl intel_rapl_perf intel_soc_dts_iosf intel_uncore intel_wmi_thunderbolt ip_tables irqbypass iTCO_vendor_support iTCO_wdt jbd2 joydev kvm kvmgt kvm_intel ledtrig_audio libahci libata libphy libps2 llc mac80211 mac_hid mbcache mdev media mei mei_me mousedev mrp nls_cp437 nls_iso8859_1 pcc_cpufreq processor_thermal_device r8169 r8822be realtek rfkill rng_core scsi_mod serio serio_raw snd snd_compress snd_hda_codec snd_hda_codec_generic snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_core snd_hda_ext_core snd_hda_intel snd_hwdep snd_pcm snd_pcm_dmaengine snd_soc_acpi snd_soc_acpi_intel_match snd_soc_core snd_soc_hdac_hda snd_soc_skl snd_soc_skl_ipc snd_soc_sst_dsp snd_soc_sst_ipc snd_timer soundcore stp syscopyarea sysfillrect sysimgblt tpm tpm_crb tpm_tis tpm_tis_core typec typec_ucsi ucsi_acpi usbhid uvcvideo vfat vfio vfio_iommu_type1 vfio_mdev videobuf2_common videobuf2_memops videobuf2_v4l2 videobuf2_vmalloc videodev wmi wmi_bmof x86_pkg_temp_thermal xhci_hcd xhci_pci x_tables

[8.2.] Processor information (from /proc/cpuinfo): (Maybe not appliable)
[8.3.] Module information (from /proc/modules): 

(Parts related to i2c and elan:)

i2c_algo_bit 16384 1 i915, Live 0x0000000000000000
i2c_hid 32768 0 - Live 0x0000000000000000
hid 147456 3 hid_generic,usbhid,i2c_hid, Live 0x0000000000000000
elan_i2c 49152 0 - Live 0x0000000000000000
i2c_i801 36864 0 - Live 0x0000000000000000

[8.4.] Loaded driver and hardware information (/proc/ioports, /proc/iomem)

/proc/ioports:
0000-0000 : PCI Bus 0000:00
  0000-0000 : dma1
  0000-0000 : pic1
  0000-0000 : iTCO_wdt
  0000-0000 : timer0
  0000-0000 : timer1
  0000-0000 : keyboard
  0000-0000 : PNP0C09:00
    0000-0000 : EC data
  0000-0000 : keyboard
  0000-0000 : PNP0C09:00
    0000-0000 : EC cmd
  0000-0000 : rtc0
  0000-0000 : dma page reg
  0000-0000 : pic2
  0000-0000 : dma2
  0000-0000 : fpu
    0000-0000 : PNP0C04:00
  0000-0000 : iTCO_wdt
  0000-0000 : pnp 00:02
0000-0000 : PCI conf1
0000-0000 : PCI Bus 0000:00
  0000-0000 : pnp 00:02
  0000-0000 : pnp 00:00
    0000-0000 : ACPI PM1a_EVT_BLK
    0000-0000 : ACPI PM1a_CNT_BLK
    0000-0000 : ACPI PM_TMR
    0000-0000 : ACPI CPU throttle
    0000-0000 : ACPI PM2_CNT_BLK
    0000-0000 : pnp 00:04
    0000-0000 : ACPI GPE0_BLK
  0000-0000 : pnp 00:01
  0000-0000 : PCI Bus 0000:08
    0000-0000 : 0000:08:00.0
  0000-0000 : PCI Bus 0000:07
    0000-0000 : 0000:07:00.0
      0000-0000 : r8822be
  0000-0000 : PCI Bus 0000:01
    0000-0000 : 0000:01:00.0
  0000-0000 : 0000:00:02.0
  0000-0000 : 0000:00:1f.4
    0000-0000 : i801_smbus
  0000-0000 : 0000:00:17.0
    0000-0000 : ahci
  0000-0000 : 0000:00:17.0
    0000-0000 : ahci
  0000-0000 : 0000:00:17.0
    0000-0000 : ahci


[8.5.] PCI information
  It seems to be long (over 700 lines) and unrelated to this regression. Omitted to avoid flooding. I've kept an archive so feel free to ask me to post it if needed.

[8.6.] SCSI information (from /proc/scsi/scsi): (Empty)
[8.7.] Other information that might be relevant to the problem:

  dmesg is constantly showing "elan_i2c i2c-ELAN061B:00: invalid report id data (d)".
  I checked the git log and it is likely to be related to commit "95df599f95f398b0a34d081dadfdee3126e58163".
  I'm using Arch Linux, its kernel repository link: [1]
  I checked the related file "elan_i2c_core.c" in Arch Linux's kernel repository [2], and it is the same as in 5.0.10 on kernel.org.
  My laptop is a Lenovo Legion Y7000.

Links:
[1]. https://git.archlinux.org/linux.git
[2]. https://git.archlinux.org/linux.git/tree/drivers/input/mouse/elan_i2c_core.c?h=v5.0.10-arch1

Please don't hesitate if more information or operation is needed.