ARM lockup during Kexec operation

[Russell King - ARM Linux]

On Fri, Apr 21, 2017 at 11:04:19PM +0000, Rudici Cazeao wrote:
> The issue is localized to  linux-3.0.51/arch\arm/mach-transcede/hotplug.c.
> 
>                 cpu_enter_lowpower();
>             platform_do_lowpower(cpu, &spurious);
>                 cpu_leave_lowpower().                                      / *  bring this CPU back into the world of cache  coherency, and then restore interrupts  */
> 
> 
> static inline void platform_do_lowpower(unsigned int cpu, int *spurious) {
>                 for (;;) {                                                                    / * there is no power-control hardware on this platform, so all we can do is put the core into WFI; this is safe as the calling code will have already disabled interrupts */
>                         wfe();
>                                 if (pen_release == cpu) {
>                                                 break;                                          / * OK, proper wakeup, we're done */
>                                 }
> 
>                                 (*spurious)++;                                         / * Getting here, means that we have come out of WFI without having been woken up - Just note it happening - when we're woken, we can report its occurrence.
>                 }
> }

Sorry, but with the above, the platform can't support suspend/resume or
kexec reliably.  It needs a proper implementation - iow, one which
actually takes the CPU offline such that it resumes as it does the very
first time we boot.

This also doesn't seem to be mainline kernel related - and searching
google for "arm/mach-transcede" brings up no relevant results,
certainly not on the first page.

-- 
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