Created attachment 71992 [details]
Various informations and system logs.
For the system in object, halt does work perfectly. Reboot seems to be able to
shut down the machine - disks and fans are turned off - but screen and leds remain on. The system results completely frozen and the only way to fix is
to force an hardware shutdown. Problem occur with both .39 and 3.0 kernels.
In attachment, there are all the system info that may turn useful. Please let me know if there is something else you need!
Probably not much we can do - its usually indicative of bios problems
Try the different reboot modes (see Documentation/kernel-parameters.txt) and report which if any help
I can confirm this bug in version 3.3.7. I have reported the bug in my distribution bug list from where I got redirected to this list.
Interestingly Ubuntu guys have solved this issue. It might be possible to look at their work and include that into the kernel.
I can provide any other information required. Please just let me know through a comment.
It seems the kernel parameter reboot=pci works for E6520 and some other Dell Latitude models. I have not tested it because I do not have that system now. Will check and report back. Meanwhile the Ubuntu link I provided above can provide some information. Please have a look.
I checked on the system today and reboot=pci kernel parameter does the trick.
Okay, it seems like *every single Dell model* needs an override over the ACPI reboot. Something here is seriously wrong, and we need to figure out what. I'm getting really sick of having a full and complete Dell product catalog in the kernel.
Yes, I agree having the complete Dell catalog in the kernel, maintaining and timely updating it is a pain. However, we should at least collect these cases into a wiki or something, which probably all distributions can refer to. A centralized information source should be the first step in my opinion.
I have contacted Dell about this. They might be able to help find the underlying problem.