Dear Linux folks,


On an Asus F2A85-M PRO, BIOS 6601 11/25/2014, with an ASM1042 SuperSpeed 
USB Host Controller [1b21:1042], and the xHCI drivers built as modules

     CONFIG_USB_XHCI_PCI=m
     CONFIG_USB_XHCI_HCD=m

`quirk_usb_handoff_xhci` takes 60 ms, which is 15 % of the time to 
reaching `run_init_process()`. I addded some prints, showing the f

     [    0.308841] pci 0000:03:00.0: PCI->APIC IRQ transform: INT A -> 
IRQ 17
     [    0.369858] pci 0000:03:00.0: handshake done with timeout = 0
     [    0.369862] pci 0000:03:00.0: hc_init reached
     [    0.369865] pci 0000:03:00.0: second handshake done
     [    0.369869] pci 0000:03:00.0: third handshake done
     [    0.369909] pci 0000:03:00.0: quirk_usb_early_handoff+0x0/0x670 
took 59661 usecs
     […]
     [    0.415223] Run /lib/systemd/systemd as init process

Is there a way to optimize this, or move it out “the hot path”?


Kind regards,

Paul