Re: [Qemu-devel] [Android-virt] [PATCH 02/12] arm: make the number of GIC interrupts configurable

[Peter Maydell]

On 27 January 2012 00:33, Rusty Russell <address@hidden> wrote:
> Peter Maydell wrote:
>> Anyway, if we would otherwise die horribly later on we should
>> catch these cases, but it would be good to have at least a comment
>> saying that these are implementation limitations rather than
>> architectural ones.
>
> Good point.  If we add an "supported" bit to each irq, we could do weird
> things, but presumably ->num_irq would still correspond to
> ITLinesNumber.
>
> I don't want to put too much of an essay in there.  How's this:
>
>        /* ITLinesNumber is represented as (N - 32) / 1.  See
>          gic_dist_readb. */
>        if (s->num_irq < 32 || (s->num_irq % 32)) {
>                hw_error("%u interrupt lines unsupported: not divisible by 
> 32\n",
>                         num_irq);

I think that's a notch too terse for my taste. How about:

        /* ITLinesNumber is represented as (N - 32) / 1 (see
         * gic_dist_readb) so this is an implementation imposed
         * restriction, not an architectural one:
         */

thanks
-- PMM