Re: 2.6.16-rt10 crash on ppc

[Ingo Molnar <mingo@elte.hu>]

* Kumar Gala <galak@kernel.crashing.org> wrote:

> The issue me actually be a driver interrupt locking bug.  The driver 
> supports three distinct interrupts for TX, RX, Error.  I asked Emin to 
> try changing the driver to use SA_INTERRUPT in the request_irq() to 
> see what happens.  I believe that when he did that it worked but hurts 
> performance.

this is the -rt kernel, with PREEMPT_RT enabled, so SA_INTERRUPT should 
make no difference. All interrupts are executed by their interrupt 
thread, and are fully preemptible:

fastcall int handle_IRQ_event(unsigned int irq, struct pt_regs *regs,
                                struct irqaction *action)
{
        int ret, retval = 0, status = 0;

        /*
         * Unconditionally enable interrupts for threaded
         * IRQ handlers:
         */
        if (!hardirq_count() || !(action->flags & SA_INTERRUPT))
                local_irq_enable();

i.e. SA_INTERRUPT should have no effect.

	Ingo