HOWTO Fix A Buggy DSDT File

**scaine** · July 6th, 2009

Do you think it would be feasible to create a python/gui program that would run iasl, generate your DSDT file, then check its contents against a web respository of such DSDT files, then give you the option to download/install a "fixed" version?

Otherwise, surely, this will potentially affect every future version of linux?

I mean, such a tool would have to be run with huge warnings regarding the potential for complete breakage, but all I'm asking is if such a tool is feasible?

**67GTA** · July 6th, 2009

I'm sure it could be done. I actually envisioned something like this when I started this thread, but don't know how to write code, and don't have any web space to host anything. If you know of someone interested then tell them to contact me.

**kevin butler** · July 8th, 2009

Well, congratulations 67GTA on creating the most productive thread I've seen in a long, long time. Kudos to you! In following your howto, I've eliminated all but one pesky error

Code:

 dsdt.dsl   776:                 Return (^C08F (Arg0, Arg1, Arg2))
 Error    4059 -                                     ^ Called method returns no value

Damn it, but I can't sort this last issue correctly. 'Tis beyond me. If you could point me in the right direction, you'd make an old compaq armada m300 very happy indeed!

**67GTA** · July 8th, 2009

kevin butler:

Compilation complete. 0 Errors, 0 Warnings, 0 Remarks, 1179 Optimizations

I added a null value to fix the last error. The method seemed to be complete. The two remarks were harmless. I changed the values from 0 to 1 to make iasl happy. After you get it done and reboot, open a terminal and edit the scrollback in the terminal preferences to 3000 instead of 512. Then post a copy of

Code:

sudo dmesg

so I can see if there are any acpi errors.

dsdt.aml.zip

EDIT: Be sure to add acpi_osi="Linux" to your grub list as shown in my first post.

**kevin butler** · July 11th, 2009

Excellent! She boots, reboots, suspends and powers off! All this, without a paragraph of kernel parameters nor any elephants raised, skinny or otherwise. This old curmudgeon of a laptop is transformed to an obedient pup with a single file. How fantastic is that. Huge thanks to you 67GTA for your time!

Code:

sudo dmesg | grep ACPI > dmesg-acpi

**67GTA** · July 11th, 2009

No ACPI errors. Glad to help!

**enomis** · July 11th, 2009

Hi, I have a Toshiba Satellite L300D-22L and I read in several forums that, generally speaking, Satellite L300Ds (and L300) may have buggy DSDT that prevent Linux from correctly managing the fan and the ACPI. In my case, the fan seems to work fine (i.e. it is on and the cpu temperature never gets warmer than 50-52C). However, I was not able to hibernate (system crashes on wake up). Therefore, I tried to fix my DSDT. I write below what I did, in case it might be useful for someone else.

When trying to recompile my dsdt.dsl, I got the following error

dsdt_old.dsl 1: ACPI LIMF, 8,
Error 4095 - ^ syntax error, unexpected PARSEOP_NAMESEG, expecting PARSEOP_DEFINITIONBLOCK

Openining my dsdt.dsl, I saw that the first two lines were:

ACPI Warning (nsaccess-0733): NsLookup: Type mismatch on INFO (RegionField), searching for (Buffer) [20081204]
ACPI Warning (nsaccess-0733): NsLookup: Type mismatch on INFO (RegionField), searching for (Buffer) [20081204]

I deleted both of them and tried to recompile dsdt.dsl. This time I got the following error:

dsdt_old.dsl 2785: And (CTRL, 0x1E)
Warning 1105 - ^ Result is not used, operator has no effect

This time I changed And (CTRL, 0x1E) to And (CTRL, 0x1E, CTRL) at line 2785. I was then able to recompile without warning and without errors. While recompiling, iasl made 18 optimizations.
My notebook is now able to hibernate and wakes up without problems. I do not know if the problem was solved by eliminating the warning of by the optimizations, but what matters is that now evereything seems to work

I decided to post this just in case someone has my same laptop or is experiencing the same problem.
However, I have one question: what do I have to do if I want to get back to my old dsdt (of which I made a back up copy of course)? To install the new one I followed the howto in the first post of this thread. How do I "uninstall" it?

I hope that my post can help someone and thanks for the answer!

**RD1** · July 12th, 2009

How do I fix these errors?

Code:

Intel ACPI Component Architecture
ASL Optimizing Compiler version 20081204 [Jan 10 2009]
Copyright (C) 2000 - 2008 Intel Corporation
Supports ACPI Specification Revision 3.0a

dsdt.dsl  1234:             Method (_WED, 1, NotSerialized)
Warning  1087 -                        ^ Not all control paths return a value (_WED)

dsdt.dsl  1234:             Method (_WED, 1, NotSerialized)
Warning  1080 -                        ^ Reserved method must return a value (_WED)

dsdt.dsl  1575:             Method (WMCA, 3, NotSerialized)
Warning  1087 -                        ^ Not all control paths return a value (WMCA)

dsdt.dsl  1673:             Method (WMCB, 3, NotSerialized)
Warning  1087 -                        ^ Not all control paths return a value (WMCB)

dsdt.dsl  1717:             Method (WMCD, 3, NotSerialized)
Warning  1087 -                        ^ Not all control paths return a value (WMCD)

dsdt.dsl  1809:             Method (WMCE, 3, NotSerialized)
Warning  1087 -                        ^ Not all control paths return a value (WMCE)

dsdt.dsl  2190:             Method (WMCF, 3, NotSerialized)
Warning  1087 -                        ^ Not all control paths return a value (WMCF)

ASL Input:  dsdt.dsl - 7550 lines, 265365 bytes, 2721 keywords
AML Output: dsdt.aml - 26843 bytes, 697 named objects, 2024 executable opcodes

Compilation complete. 0 Errors, 7 Warnings, 0 Remarks, 844 Optimizations

Thanks