# 2 Seconds missing: Kernel ACPI AE_ERROR

## willsteel

Hey,

Im a pedantic guy that wants to sqeeze out anything of my system. Today i tried to reduce boot time, with some luck. 

But, I noticed an unwanted two seconds delay when doing the ACPI stuff. It points out some errors:

```
...

[    0.230116] [Firmware Bug]: ACPI: BIOS _OSI(Linux) query ignored

[    2.229034] ACPI Exception: AE_ERROR, Returned by Handler for [PCI_Config] (20120913/evregion-501)

[    2.229044] ACPI Error: ;ethod parse/exception failed [\_SB_.PC10.ZYXW] 

....
```

Unfortunately, this doesnt say anything to me. So I dont know where to start looking. So my question is: 

"does anyone know whant this means? and is it fixable?"

p.s.: using gentoo sources 3.7.10 on a MacBook9.2    Core2 i5

regards,

Michael

UPDATE: The second line causes the delay (ACPI Exception: AE_ERROR...). The first one is known and only posted to see the timestamps.Last edited by willsteel on Tue Mar 12, 2013 7:06 pm; edited 2 times in total

----------

## eyoung100

Ubuntu Bug [Closed]

Ubuntu Forum Post

----------

## willsteel

Actually, the next line is the one thats causing the delay. The OSI error is harmless and does not explain the delay. I only posted it for the timestamps to see theres a two seconds delay.

btw, i can use google :>

Michael

----------

## eyoung100

You miss the point.  The error is caused by the bad firmware Exception.  I know this because the BIOS revision date is in the error:

13-SEP-2012.

Go to Apple's Support site and see if they have an update for your bios.  If I had to guess Apple has gzipped your /proc/pci file into the BIOS in order to speed up the booting of OSX, and the file resides in event region 501.  501 is the lower band of Kernel RAM for the ACPI Interface.  Let your boot finish, then type dmesg All the Stuff at the top of the DMESG that says Address Space Blah and Reserved Blah is the reserved ACPI space.  You don't see it on OSX boot because there is no way to disable the NeXT GUI.  Same with Windows.  The 2 second delay is the timeout period between when the query is executed and he kernel says I dunno what to do with this so I'll just ignore it.

----------

## willsteel

Yep, 

you were right. Problem is that due to "modification" of the MacBoock (other HDD and RAM) the correct update for my mac refuses to install (funny).

So what i did is to tweak the timeout value from 2000ms to 200ms which seems fast enough for me:

```
"ACPI_MAX_SLEEP" in: "/usr/src/linux/include/acpi/aaconfig.h" set to "200"
```

thanks,

Michael

----------

