Hello everyone,

starting with Linux Kernels 3.19, there is a bug, which leads to a system hang for about 3 seconds, when booting Linux. During the hang, the system is absolutely unresponsive and the fans run at max speed (around 5000 rpm). The system also hangs, when you want to monitor temperatures. It has to do with SMM calls, caused by the "dell-smm-hwmon" module. A more detailed bug report can be found on the official Linux Kernel bugtracker: 
https://bugzilla.kernel.org/show_bug.cgi?id=112021

It's a BIOS related bug, so I would kindly ask the Dell developers look into it. Ubuntu 14.04.2 LTS is not affected, as Kernel 3.16 is used, but later Ubuntu versions, including 14.04.3 LTS (Kernel 3.19) and 14.04.4 LTS (Kernel 4.2) are affected. However, I want to make clear, that this issue is not limited to Ubuntu, but affects all Linux distributions using Kernel above 3.19.

I'm also fine, if you can redirect me to the correct people or give me a name atleast, if no one can help me here.

Cheers,

Tolga