Re: [ANNOUNCE] 3.0.1-rt11

On Wed, Sep 07, 2011 at 11:25:29AM +0200, Thomas Gleixner wrote:

This smells badly like the problem we've seen on x86 before. And
looking at the arm SMP boot code:

asmlinkage void __cpuinit secondary_start_kernel(void)
{
	.....

	/*
	 * Give the platform a chance to do its own initialisation.
	 */
	platform_secondary_init(cpu);

	/*
	 * Enable local interrupts.
	 */
	notify_cpu_starting(cpu);
	local_irq_enable();

Here we enable interrupts, but the CPU is neither online nor active.

	local_fiq_enable();

That's intentional.  Some of the code below needs IRQs enabled.

I think we had this reported before and I got to the bottom of it - the
platform was doing something it shouldn't.  I don't remember the details,
maybe when all the emails come through I can see the original bug report
I'll remember.