Re: [microblaze-uclinux] why intr->ack() is null?

[Yasushi SHOJI <yashi@xxxxxxxxxxxxxxxxx>]

At Wed, 02 Jun 2004 16:30:21 +1000,
John Williams wrote:
> 
> John Williams wrote:
> > 
> > I looked at the V2Pro/PPC source as well, and their driver for the 
> > XINTC, and it shows the same uncertainty about the behaviour of the 
> > XINTC. Their source is available (via bitkeeper) from penguinppc.org.  I 
> > can send you the specific source file if you want to look into it.
> > 
> 
> I just checked again, they've updated the source.  Grab the PPC 
> xilinx_intc driver into your current working dir with this command:
> 
> rsync -avz --delete 
> source.mvista.com::linuxppc_2_4_devel/arch/ppc/kernel/xilinx_pic.c .
> 
> and see what they've done.  Basically if it's a level sensitive 
> interrupt they ack after, else they ack immediately.  Smells like a hack 
> to me.

ok here is the portion of it (just as a record):

static void
xilinx_intc_disable_and_ack(unsigned int irq)
{
        unsigned long mask = (0x80000000 >> (irq & 31));
        // printk(KERN_INFO "disable_and_ack: %d\n", irq);
        intc_out_be32(intc + CIE, mask);
        if (xilinx_intc_kind_of_intr(mask) != 0)
                intc_out_be32(intc + IAR, mask); /* ack edge triggered intr */
}

static void
xilinx_intc_end(unsigned int irq)
{
        unsigned long mask = (0x80000000 >> (irq & 31));

        // printk(KERN_INFO "end: %d\n", irq);
        if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
                intc_out_be32(intc + SIE, mask);
                /* ack level sensitive intr */
                if(xilinx_intc_kind_of_intr(mask) == 0)
                        intc_out_be32(intc + IAR, mask);
        }
}

as you said, this smells like a hack. I'll pound my head a bit more
about this ;)

Thanks for the info, John.

regards,
--
              yashi
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