Messages in this thread | | | Date | Sat, 6 Aug 2011 16:30:03 +0100 | From | Matthew Garrett <> | Subject | Re: [PATCH] x86: Add reboot quirk for Dell Precision M4600 |
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On Sat, Aug 06, 2011 at 08:56:35AM +0200, Ingo Molnar wrote: > Weird - ACPI is the default Windows method of reboot - how come it > does not work on that box? Does Windows work around this specific > machine (unlikely), or is our ACPI boot sequence not 100% compatible > with the Windows method (more likely IMO)?
The ACPI reboot method on these machines hits the keyboard controller rather than PCI, which is unusual. What I suspect is that the write triggers some SMM or EC code that's making assumptions about system state, and we're not quite identical. Bouncing on the keyboard controller from userspace with init=/bin/bash wedges in the same way.
-- Matthew Garrett | mjg59@srcf.ucam.org
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