ACPI: Only use IPI on known broken machines (AMD, Dothan/BaniasPentium M)
Use IPI for blacklisted CPUs, add parameter IPI vs LAPIC Currently, Linux disables lapic timer for all machines with C2 and higher C-state support. According to Intel only specific Intel models (Banias/Dothan) are broken in respect of not waking up from C2 with lapic. However, I am not sure about the naming of the parameter and how it could/should get integrated into the dyntick part (CONFIG_GENERIC_CLOCKEVENTS). There, a more fine grained check (TSC still running?, ..) is needed? Does this make sense (always use CLOCK_EVT_NOTIFY_BROADCAST_ON, but use OFF if forced by use_ipi=0: clockevents_notify(use_ipi ? CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF, &pr->id); Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Len Brown <len.brown@intel.com>
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