Re: [RFC PATCH V2 1/8] irqdomain: Ensure type settings match for an existing mapping

[Linus Walleij]

On Tue, Dec 22, 2015 at 10:58 AM, Linus Walleij
<linus.walleij@xxxxxxxxxx> wrote:
> On Fri, Dec 18, 2015 at 11:10 AM, Jon Hunter <jonathanh@xxxxxxxxxx> wrote:
>> On 17/12/15 13:16, Linus Walleij wrote:
>>> On Thu, Dec 17, 2015 at 11:48 AM, Jon Hunter <jonathanh@xxxxxxxxxx> wrote:
>>>> +               } else {
>>>> +                       virq = irq_domain_alloc_descs(-1, 1, hwirq,
>>>> +                                                     of_node_to_nid(of_node));
>>>
>>> What is this all of a sudden? Not even mentioned in the
>>> commit. Plus I bet ACPI need something else than OF nid
>>> passed here.
>>
>> Do you mean the else part of all of the above?
>
> Yes
>
>> So in the current code, the else part calls irq_create_mapping() (...)
>
> No, not that... The fact that you all of a sudden have started
> calling irq_domain_alloc_descs() which the function didn't do
> before, totally changing the calling semantics for everyone in
> the kernel, leading to the problem I then describe with this
> potentially being called before the irqdomain for the irqchip
> is initialized and descs getting "random" numbers.

I see I didn't go into those details in my first answer. Hm, I
guess I got uncertain and deleted it because I remember
writing it...

I am simply worries that starting to call irq_domain_alloc_descs()
has unintended side effects, especially on platforms using
legacy or simple irqdomains.

Yours,
Linus Walleij
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/