Messages in this thread | | | Date | Mon, 21 Jan 2013 23:01:06 -0800 | Subject | Re: [PATCH] powerpc/pasemi: Fix crash on reboot | From | Olof Johansson <> |
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Hi,
On Mon, Jan 21, 2013 at 7:23 PM, Steven Rostedt <rostedt@goodmis.org> wrote: > commit f96972f2dc "kernel/sys.c: call disable_nonboot_cpus() in > kernel_restart()" > > added a call to disable_nonboot_cpus() on kernel_restart(), which tries > to shutdown all the CPUs except the first one. The issue with the PA > Semi, is that it does not support CPU hotplug. > > When the call is made to __cpu_down(), it calls the notifiers > CPU_DOWN_PREPARE, and then tries to take the CPU down. > > One of the notifiers to the CPU hotplug code, is the cpufreq. The > DOWN_PREPARE will call __cpufreq_remove_dev() which calls > cpufreq_driver->exit. The PA Semi exit handler unmaps regions of I/O > that is used by an interrupt that goes off constantly > (system_reset_common, but it goes off during normal system operations > too). I'm not sure exactly what this interrupt does.
On this version of the power architecture, the system comes back through the reset vector when returning from some of the lower-power idle states, which should be why you see those exceptions go off.
Thanks for catching this. I have a system that I try booting a few times every release cycle, but I must have missed checking if reboots still work. Glad to see you're keeping yours alive, it's becoming a collectible. :-)
[...]
> Cc: Olof Johansson <olof@lixom.net> > Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Olof Johansson <olof@lixom.net>
Ben, please apply for 3.8.
-Olof
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