Document workaround for soft lockup with Dell XPS 15 9560 and NVidia pascal

A user reported being showed a “soft lockup - CPU#X stuck for 22s” at boot with a Dell XPS 15 9560, with a core i7-7700 dual GPU (Intel HD Graphics 630 and NVIDIA GeForce GTX 1050).

just using the nouveau.modeset=0 parameter didn’t solve the issue, however, the following parameters did :

acpi_osi=linux acpi_backlight=vendor nouveau.modeset=0

there is an extended thread about this laptop’s linux support here :
https://bbs.archlinux.org/viewtopic.php?id=223056

note that another user with an Asus ux550 (same chipset, proc and GPUs) saw the same issue, unfortunately, even if tails can boot with them, the boot parameters break the screen backlight.

Related issues

• Blocks #15507 (closed)

Original created by @goupille on 15774 (Redmine)