More irqdomain problems (Was: next/mmotm unbootable on G5: irqdomain)

[Grant Likely]

On Mon, Jul 23, 2012 at 12:32 AM, Benjamin Herrenschmidt
<benh at kernel.crashing.org> wrote:
> Allright, another one Grant:
>
> unsigned int irq_find_mapping(struct irq_domain *domain,
>                               irq_hw_number_t hwirq)
> {
>         struct irq_data *data;
>
>         /* Look for default domain if nececssary */
>         if (domain == NULL)
>                 domain = irq_default_domain;
>         if (domain == NULL)
>                 return 0;
>
>         switch (domain->revmap_type) {
>         case IRQ_DOMAIN_MAP_LEGACY:
>                 return irq_domain_legacy_revmap(domain, hwirq);
>         case IRQ_DOMAIN_MAP_LINEAR:
>                 return irq_linear_revmap(domain, hwirq);
>         case IRQ_DOMAIN_MAP_TREE:
>                 rcu_read_lock();
>                 data = radix_tree_lookup(&domain->revmap_data.tree, hwirq);
>                 rcu_read_unlock();
>                 if (data)
>                         return data->irq;
> -               break;
> +               return 0;
>         case IRQ_DOMAIN_MAP_NOMAP:
>
> Please, stick a proper commit message and my s-o-b and see if you can fix
> your tree before you ask Linus to pull because that's not pretty on any
> pseries .... irq_find_mapping() does get called for all interrupt the
> first time it's mapped to check if there's a pre-existing mapping, so
> the case of the thing being unpopulated is absolutely legit.
>
> the NOMAP case has a similar dubious exit case but since I'm not that
> familiar with NOMAP I haven't touched it.

I've decided to rework the patch to simply omit the WARN statement. It
isn't really needed. I've merged in Linus' tree below the eliminate
slow-path patch and remove the WARN statement. It's been pushed out to
my irqdomain/next branch, so it should show up in tomorrow's
linux-next.

You can find it here if you want to give it a spin:

git://git.secretlab.ca/git/linux-2.6 irqdomain/next

I'll give it a bit more time in linux-next before I ask Linus to pull.

g.