Why does disabling ATA fix "run_interrupt_driven_hooks still waiting after 60 seconds for xpt_config" in FreeBSD?

Question

Why did it work?

Why did the 5. step solve the problem? What is so special about disabling ATA which removed the run_interrupt_driven_hooks still waiting after 60 seconds for xpt_config error?

My optical disk drive is Samsung CD-RW / DVD ts-l462d if it helps. I couldn't find whether this drive is supported by FreeBSD 10.2.

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Background

The problem is quite complex:

1. I wanted to install FreeBSD 10.2 on an old laptop (Hasee Q540s) using the FreeBSD 10.2 RELEASE i386 DVD1 image.
2. I've managed to boot the installer and install FreeBSD after choosing Safe Mode in the welcome screen.

3. With FreeBSD installed on my hard disk I decided to boot try to boot it normally. I failed because FreeBSD freezed during booting after showing me this message:

   run_interrupt_driven_hooks still waiting after 60 seconds for xpt_config

4. According to the Internet this error is connect with FireWire. Here are some solutions I found online:

   • Disable FireWire in BIOS - I can't do it on this laptop. My BIOS doesn't have such options.

   • Because this is the issue with FireWire I've tried to add kldunload firewire and kldunload sbp to /boot/loader.conf. It didn't work although the /boot/loader.conf has been properly loaded according to the logs. Being a little bit frustrated by then, I decided to build my own kernel without the sbp, firewire and fwe modules. Didn't work as well.

5. Finally, I've found a post called Problem after upgrading... how to disable USB?. I decided to append

   hint.ata.0.disabled="1"
   hint.ata.1.disabled="1"
   

   to the /boot/device.hints file.

6. And it worked; I can boot without Safe Mode on!