Comment 29 for bug 1203592

Simon,

It looks like your UEFI variable has a different name:

KBDBacklitLvl-8be4df61-93ca-11d2-aa0d-00e098032b8c

Please do xxd on this and see if it looks similar to my SecKeyboardBacklightLevel variable.

Thanks for your DSDT. It looks like your machine doesn't have a KBLL variable... the closest thing I could find was a KBCL variable, but I have no idea if it does the same thing.

I have uploaded a program to probe the memory at this region, designed for your DSDT, at:

https://github.com/kieranclancy/probe-dsdt-regions/tree/900x3g

(Note to others, do NOT run this program, it is just for Simon's DSDT and could break your system. If you want a version of this program for your machine's DSDT, please ask me.)

If you have time, can you please:

1. Compile this program from the 900x3g branch
2. Reboot to get a relatively clean variable state
3. Save the output of 'sudo ./probe'
4. Dump the KBDBacklitLvl UEFI variable with xxd and save this too.
5. Modify the KBDBacklitLvl variable slightly (e.g. from 00 00 00 07 to 00 00 00 06)
6. Reboot to reload variables
7. Save the output of 'sudo ./probe' to a new file

This will tell me whether your KBCL variable is the important one, or if the variable has another name.

At some point I would like to handle these KBLL/KBCL variables in the kernel, and this information from your machine can help me to write a safe kernel module to do this.