Created attachment 294035 [details]
Linux 5.9.11 messages (output of `dmesg`)

On the Dell Precision 3540/0M14W7, BIOS 1.9.1 07/06/2020, `acpi_init()` takes over 600 ms. That is 85 % of the Linux kernel start up to unpacking the initrd.

```
[    0.000000] microcode: microcode updated early to revision 0xde, date = 2020-05-18
[    0.000000] Linux version 5.9.0-4-amd64 (debian-kernel@lists.debian.org) (gcc-10 (Debian 10.2.0-19) 10.2.0, GNU ld (GNU Binutils for Debian) 2.35.1) #1 SMP Debian 5.9.11-1 (2020-11-27)
[…]
[    0.143609] ACPI: Added _OSI(Module Device)
[    0.143609] ACPI: Added _OSI(Processor Device)
[    0.143609] ACPI: Added _OSI(3.0 _SCP Extensions)
[    0.143609] ACPI: Added _OSI(Processor Aggregator Device)
[    0.143609] ACPI: Added _OSI(Linux-Dell-Video)
[    0.143609] ACPI: Added _OSI(Linux-Lenovo-NV-HDMI-Audio)
[    0.143609] ACPI: Added _OSI(Linux-HPI-Hybrid-Graphics)
[    0.187737] ACPI: 12 ACPI AML tables successfully acquired and loaded
[    0.251625] ACPI: [Firmware Bug]: BIOS _OSI(Linux) query ignored
[    0.260957] ACPI: Dynamic OEM Table Load:
[    0.260963] ACPI: SSDT 0xFFFF90A081E92500 0000F4 (v02 PmRef  Cpu0Psd  00003000 INTL 20160527)
[    0.262517] ACPI: \_SB_.PR00: _OSC native thermal LVT Acked
[    0.263717] ACPI: Dynamic OEM Table Load:
[    0.263724] ACPI: SSDT 0xFFFF90A081EAEC00 000400 (v02 PmRef  Cpu0Cst  00003001 INTL 20160527)
[    0.265231] ACPI: Dynamic OEM Table Load:
[    0.265236] ACPI: SSDT 0xFFFF909B0739C000 000560 (v02 PmRef  Cpu0Ist  00003000 INTL 20160527)
[    0.266688] ACPI: Dynamic OEM Table Load:
[    0.266691] ACPI: SSDT 0xFFFF90A081EFDC00 00011B (v02 PmRef  Cpu0Hwp  00003000 INTL 20160527)
[    0.267949] ACPI: Dynamic OEM Table Load:
[    0.267955] ACPI: SSDT 0xFFFF909B0739D000 000724 (v02 PmRef  HwpLvt   00003000 INTL 20160527)
[    0.269506] ACPI: Dynamic OEM Table Load:
[    0.269511] ACPI: SSDT 0xFFFF909B07399800 0005FC (v02 PmRef  ApIst    00003000 INTL 20160527)
[    0.270736] ACPI: Dynamic OEM Table Load:
[    0.270740] ACPI: SSDT 0xFFFF90A081EABC00 000317 (v02 PmRef  ApHwp    00003000 INTL 20160527)
[    0.271957] ACPI: Dynamic OEM Table Load:
[    0.271962] ACPI: SSDT 0xFFFF909B07D57000 000AB0 (v02 PmRef  ApPsd    00003000 INTL 20160527)
[    0.273645] ACPI: Dynamic OEM Table Load:
[    0.273649] ACPI: SSDT 0xFFFF90A081EAB800 00030A (v02 PmRef  ApCst    00003000 INTL 20160527)
[    0.277047] ACPI: EC: EC started
[    0.277047] ACPI: EC: interrupt blocked
[    0.290401] ACPI: EC: EC_CMD/EC_SC=0x934, EC_DATA=0x930
[    0.290403] ACPI: \_SB_.PCI0.LPCB.ECDV: Boot DSDT EC used to handle transactions
[    0.290404] ACPI: Interpreter enabled
[    0.290440] ACPI: (supports S0 S3 S4 S5)
[    0.290441] ACPI: Using IOAPIC for interrupt routing
[…]
[    0.743154] ACPI: PCI Interrupt Link [LNKH] (IRQs 3 4 5 6 10 11 12 14 15) *0
[    0.756402] ACPI: EC: interrupt unblocked
[    0.756402] ACPI: EC: event unblocked
[    0.756409] ACPI: EC: EC_CMD/EC_SC=0x934, EC_DATA=0x930
[    0.756409] ACPI: EC: GPE=0x6e
[    0.756411] ACPI: \_SB_.PCI0.LPCB.ECDV: Boot DSDT EC initialization complete
[    0.756411] ACPI: \_SB_.PCI0.LPCB.ECDV: EC: Used to handle transactions and events
[…]
[    0.795501] Trying to unpack rootfs image as initramfs...
```