XPS 9310 Developer Edition with Ubuntu 20.04 will not fully suspend
I have a brand new 9310 with the latest BIOS 3.03 and with the factory Ubuntu 20.04 ISO from Dell, I haven't installed anything or made any big modification to the system, only the Ubuntu Software Updates.
When I press Suspend, it will Suspend but the bottom of the laptop will always stay WARM, meaning it is not really in Suspend mode, even if I remove the USB-C charger cable and leave it only with battery, it will continue WARM, meaning overtime it will drain the battery super fast.
Is there something I can do to address this problem so the laptop can properly enter into Suspend/Sleep mode.
On me system (9300 that came with Ubuntu) I had to do the following changes :
BIOS, turn off Early Logo Display to OFF in the Sign of Life options
BIOS, disable Secure Boot
In the system, edit and configure in /etc/default/grub to add to the kernel options : mem_sleep_default=deep
My current kernel options are : GRUB_CMDLINE_LINUX_DEFAULT="quiet splash mitigations=off mem_sleep_default=deep"
(do NOT use mitigations=off unless you seriously know what you're doing)
Reboot. TO check if the deep sleep is on :
Should return :
The deep here confirms the deep sleep mode is turned on.
On my 9300 I can close the lid at 100 % and after a full day of sleep, I will be at 99 or 98 % of battery at the end of the day.
I did not edit the /etc/systemd/sleep.conf file at all. The kernel option is enough.
Note : after the 9300 model Dell has broken the deep sleep and it's no longer available in the UEFI table so there's no way to turn on deep sleep on those models. The 9300 is the last model where the deep sleep works properly. Which also means my next laptop is a X Carbon from another brand.
Dell, you lost a customer that spent 3000 euro per year to another brand. Congratulations.