cmbat related ACPI change between 6.0-release and Nov 10th -stable sources is making Dell laptops to hang

[Pierre-Luc Drouin]

Hi,

Since I upgraded from 6.0-release to 6.0-stable on Nov 10th, my laptop 
hangs for about 1-2 seconds everytime a battery monitoring tool asks for 
the cmbat battery status. My laptop is a Dell Precision M70 and shares 
its motherboard with many other Dell laptops. I can reproduce the 
problem by running "acpiconf -i loop" or "sysctl hw.acpi.battery.life". 
The problem did not exist with 6.0-release, so it has been caused by 
some code change between -release and Nov 10th sources. Disabling cmbat 
with debug.acpi.disabled avoids the laptop to hang. Does someone know 
what change to cmbat related stuff could be causing this problem?

Thank you!

Pierre-Luc Drouin