Dell l321x Touchpad problems

Hello, The touchpad on the Dell l321x XPS 13 is buggy since the change from synaptics to libinput (Ubuntu 17.10 to 18.04).

This is my kernel:

fredo@fredo-Dell-System-XPS-L321X:~$ uname -r
4.18.0-18-generic

This is my touchpad

fredo@fredo-Dell-System-XPS-L321X:~$ dmesg|grep -i "ps/2"
[    1.010830] i8042: PNP: PS/2 Controller [PNP0303:PS2K,PNP0f13:PS2M] at 0x60,0x64 irq 1,12
[    1.015179] mousedev: PS/2 mouse device common for all mice
[    2.620765] input: CyPS/2 Cypress Trackpad as /devices/platform/i8042/serio1/input/input6

This is my libinput version :

> fredo@fredo-Dell-System-XPS-L321X:~$ dpkg -s libinput10 | grep Version
> Version: 1.10.4-1

This is my initial test:

fredo@fredo-Dell-System-XPS-L321X:~$ sudo libinput measure touchpad-pressure
[sudo] password for fredo: 
Using CyPS/2 Cypress Trackpad: /dev/input/event10

Ready for recording data.
Pressure range used: 30:25
Palm pressure range used: 130
Place a single finger on the touchpad to measure pressure values.
Ctrl+C to exit


Sequence 1183 pressure: min:  37 max: 110 avg:  83 median:  89 tags: down
Sequence 1184 pressure: min:  24 max: 143 avg:  96 median:  92 tags: down palm
Sequence 1185 pressure: min:  41 max:  97 avg:  70 median:  68 tags: down
Sequence 1186 pressure: min:  15 max: 147 avg:  85 median:  83 tags: down palm
This tool cannot handle multiple fingers, output will be invalid
Sequence 1188 pressure: min:  65 max: 112 avg:  91 median:  90 tags: down
Sequence 1188 pressure: min:  36 max: 189 avg: 101 median:  95 tags: down palm
Sequence 1189 pressure: min:   9 max: 156 avg:  99 median: 100 tags: down palm
Sequence 1190 pressure: min:  21 max: 153 avg: 100 median: 106 tags: down palm
Sequence 1191 pressure: min:  30 max: 204 avg: 115 median: 108 tags: down palm
Sequence 1192 pressure: min:  37 max: 104 avg:  81 median:  83 tags: down

I just run a test using 30:20 and 254 which seems to help the touchpad a lot. Before you had to move it slowly or it would get stuck.

sudo libinput measure touchpad-pressure -touch-thresholds=30:20 --palm-threshold=254
[sudo] password for fredo: 
Using CyPS/2 Cypress Trackpad: /dev/input/event10

Ready for recording data.
Pressure range used: 30:20
Palm pressure range used: 254
Place a single finger on the touchpad to measure pressure values.
Ctrl+C to exit

Sequence 865 pressure: min:  53 max: 136 avg:  96 median:  96 tags: down
Sequence 866 pressure: min:  32 max: 130 avg:  96 median:  97 tags: down
Sequence 867 pressure: min:  45 max: 130 avg:  86 median:  89 tags: down
Sequence 868 pressure: min:  31 max: 101 avg:  78 median:  77 tags: down
Sequence 869 pressure: min:  28 max:  99 avg:  75 median:  78 tags: down
Sequence 870 pressure: min:  33 max: 129 avg:  90 median:  90 tags: down
Sequence 871 pressure: min:  22 max: 125 avg:  91 median:  96 tags: down
Sequence 872 pressure: min:  23 max: 100 avg:  69 median:  67 tags: down
Sequence 873 pressure: min:  31 max:  84 avg:  71 median:  76 tags: down
Sequence 874 pressure: min:  45 max:  89 avg:  64 median:  66 tags: down
Sequence 875 pressure: min:  56 max: 103 avg:  89 median:  93 tags: down
Sequence 876 pressure: min:  52 max: 123 avg:  99 median: 101 tags: down
Sequence 877 pressure: min:  24 max: 105 avg:  79 median:  79 tags: down
Sequence 878 pressure: min:  43 max: 123 avg:  85 median:  84 tags: down
Sequence 879 pressure: min:  54 max: 135 avg:  88 median:  86 tags: down
Sequence 880 pressure: min:  40 max:  96 avg:  75 median:  76 tags: down
Sequence 881 pressure: min:  19 max:  93 avg:  60 median:  55 tags: down
Sequence 882 pressure: min:  30 max:  98 avg:  79 median:  84 tags: down
Sequence 883 pressure: min:  21 max:  96 avg:  71 median:  70 tags: down
Sequence 884 pressure: min:  48 max:  91 avg:  79 median:  81 tags: down
Sequence 885 pressure: min:  33 max: 100 avg:  84 median:  87 tags: down
Sequence 886 pressure: min:  50 max: 106 avg:  78 median:  78 tags: down
Sequence 887 pressure: min:  28 max:  75 avg:  55 median:  56 tags: down

I am not so sure how to modify /sys/class/dmi/id/modalias , because I believe it's a virtual file?? The other problem I have is that I am unable to click and drag. I am not sure on how to get that troubleshooted..

Let me know if I can help somehow. The bug is also reported here https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1816947; https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1819242 Thanks