Comment 42 for bug 129226

It's not really fixed. Speedstepping the second core fails after suspend, but it does not crash.

The log shows:
[ 4754.680000] CPU: Processor Core ID: 1
[ 4754.680000] CPU1: Intel(R) Core(TM)2 Duo CPU T7300 @ 2.00GHz stepping 0a
[ 4754.680000] ACPI Error (psloop-0136): Found unknown opcode FE at AML address f88523ca offset 3, ignoring [20070126]
[ 4754.680000] ACPI Error (psargs-0355): [C\376\377\376.D\376\377] Namespace lookup failure, AE_NOT_FOUND
[ 4754.680000] ACPI Error (psparse-0551): Method parse/execution failed [\_PR_.CPU1._PCT] (Node df816870), AE_NOT_FOUND
[ 4754.680000] ACPI Exception (processor_perflib-0170): AE_NOT_FOUND, Evaluating _PCT [20070126]
[ 4754.680000] CPU1 is up
[ 4754.684000] Switched to high resolution mode on CPU 1
[ 4754.724000] ACPI: PCI Interrupt 0000:00:02.0[A] -> GSI 16 (level, low) -> IRQ 16

$ cat /proc/cpuinfo |grep ...
cpu family : 6
model : 15
model name : Intel(R) Core(TM)2 Duo CPU T7300 @ 2.00GHz
cpu MHz : 800.000

cpu family : 6
model : 15
model name : Intel(R) Core(TM)2 Duo CPU T7300 @ 2.00GHz
cpu MHz : 1995.106

$ sudo cpufreq-info
cpufrequtils 002: cpufreq-info (C) Dominik Brodowski 2004-2006
Report errors and bugs to <email address hidden>, please.
analyzing CPU 0:
  driver: acpi-cpufreq
  CPUs which need to switch frequency at the same time: 0
  hardware limits: 800 MHz - 2.00 GHz
  available frequency steps: 2.00 GHz, 2.00 GHz, 1.60 GHz, 1.20 GHz, 800 MHz
  available cpufreq governors: conservative, ondemand, userspace, powersave, performance
  current policy: frequency should be within 800 MHz and 2.00 GHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency is 800 MHz (asserted by call to hardware).
analyzing CPU 1:
  no or unknown cpufreq driver is active on this CPU

I repeat: The second core does *not* crash - it is available with full speed, only frequency scaling fails.

If you need some more information, please let me know.