Long boot time on Dell XPS 13 9350

I installed Xubuntu 17.04 on my Dell XPS 13 9350. It looks like everything works fine except one thing. The boot time is more than 100 seconds. Here is the dmesg output. Scroll it to line 914:

[    4.192005] brcmfmac 0000:3a:00.0 wlp58s0: renamed from wlan0
[   93.322099] ACPI: Invalid package element [0]: got number, expecting [R]

This looks like something gets timed out during boot time. How can I fix this?