`pci_apply_final_quirks()` taking half a second

[Paul Menzel <pmenzel@molgen.mpg.de>]

Dear Linux folks,


Measuring where time is spent during boot with `systemd-bootchart` on an 
Asus A780FullHD, it turns out that half a second is spent in 
`pci_apply_final_quirks()`.

Here are the times copied from the SVG:

   init_ladder 0.012s
   init_menu 0.012s
   pm_sysrq_init 0.012s
   acpi_init 0.027s
   pci_subsys_init 0.008s
   hpet_late_init 0.004s
   tracer_init_tracefs 0.002s
   event_trace_init 0.008s
   pnpacpi_init 0.002s
   chr_dev_init 0.003s
   init_acpi_pm_clocksource 0.004s
   pci_apply_final_quirks 0.452s
   populate_rootfs 0.400s
   pci_iommu_init 0.003s
   rsa_init 0.058s
   serial8250_init 0.020s
   i8042_init 0.003s
   load_system_certificate_list 0.002s
   ata_init 0.007s
   ehci_pci_init 0.030s
   ohci_pci_init 0.312s
   ahci_pci_driver_init 0.342s
   atiixp_pci_driver_init 0.337s
   hid_init 0.004s
   init_sr 0.031s

I don’t know what information you need, so I just include the Linux 
Kernel version, and the output of `lspci -nn`.

```
$ more /proc/version
Linux version 4.9.0-0.bpo.2-amd64 (debian-kernel@lists.debian.org) (gcc 
version 4.9.2 (Debian 4.9.2-10) ) #1 SMP Debian 4.9.13-1~bpo8+1 (201
7-02-27)
$ lspci -nn
00:00.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] RS780 
Host Bridge [1022:9600]
00:01.0 PCI bridge [0604]: ASRock Incorporation Device [1849:9602]
00:09.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] 
RS780/RS880 PCI to PCI bridge (PCIE port 4) [1022:9608]
00:0a.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] 
RS780/RS880 PCI to PCI bridge (PCIE port 5) [1022:9609]
00:11.0 SATA controller [0106]: Advanced Micro Devices, Inc. [AMD/ATI] 
SB7x0/SB8x0/SB9x0 SATA Controller [AHCI mode] [1002:4391]
00:12.0 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD/ATI] 
SB7x0/SB8x0/SB9x0 USB OHCI0 Controller [1002:4397]
00:12.1 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD/ATI] 
SB7x0 USB OHCI1 Controller [1002:4398]
00:12.2 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD/ATI] 
SB7x0/SB8x0/SB9x0 USB EHCI Controller [1002:4396]
00:13.0 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD/ATI] 
SB7x0/SB8x0/SB9x0 USB OHCI0 Controller [1002:4397]
00:13.1 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD/ATI] 
SB7x0 USB OHCI1 Controller [1002:4398]
00:13.2 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD/ATI] 
SB7x0/SB8x0/SB9x0 USB EHCI Controller [1002:4396]
00:14.0 SMBus [0c05]: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 SMBus 
Controller [1002:4385] (rev 3a)
00:14.1 IDE interface [0101]: Advanced Micro Devices, Inc. [AMD/ATI] 
SB7x0/SB8x0/SB9x0 IDE Controller [1002:439c]
00:14.2 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] 
SBx00 Azalia (Intel HDA) [1002:4383]
00:14.3 ISA bridge [0601]: Advanced Micro Devices, Inc. [AMD/ATI] 
SB7x0/SB8x0/SB9x0 LPC host controller [1002:439d]
00:14.4 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 
PCI to PCI Bridge [1002:4384]
00:14.5 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD/ATI] 
SB7x0/SB8x0/SB9x0 USB OHCI2 Controller [1002:4399]
00:18.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] K8 
[Athlon64/Opteron] HyperTransport Technology Configuration [1022:1100]
00:18.1 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] K8 
[Athlon64/Opteron] Address Map [1022:1101]
00:18.2 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] K8 
[Athlon64/Opteron] DRAM Controller [1022:1102]
00:18.3 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] K8 
[Athlon64/Opteron] Miscellaneous Control [1022:1103]
01:05.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. 
[AMD/ATI] RS780 [Radeon HD 3200] [1002:9610]
04:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. 
RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] 
(rev 02)
```

It’d be great, if the times could be reduced, so that the time from GRUB 
to entering the LUKS passphrase gets smaller.


Kind regards,

Paul