Using kexec on a dual-core arm processor (arm7), the non-boot CPU (CPU1) appears to be locking up during kexec.
The SoC is mach-transcede?
The kernel version is 3.0.51-rt75
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.
??????????????? }
}
When the issue occurs the non-boot CPU (ie CPU 1) is entering the platform_do_lowpower sequence where it should wait until pren_release is set to 1 by? CPU1
Please note that? This failure is random. It usually happens somewhere between 300 and 5000 kexec loops.
