After some preliminary testing with kernel 4.0, it seems that the bug is fixed. I'll do more testing tomorrow. However, I've been getting the following error message at startup when using kernel 4.0.
Error parsing PCC subspaces from PCCT.
Starting version 219
thinkpad_acpi: unsupported brightness interfaces, please contact <email address hidden>
After some preliminary testing with kernel 4.0, it seems that the bug is fixed. I'll do more testing tomorrow. However, I've been getting the following error message at startup when using kernel 4.0.
Error parsing PCC subspaces from PCCT.
Starting version 219
thinkpad_acpi: unsupported brightness interfaces, please contact <email address hidden>
It doesn't affect anything of the system so far.