Re: [PATCH v5 0/5] Functional dependencies between devices

From: Lukas Wunner
Date: Fri Oct 28 2016 - 05:39:29 EST


On Thu, Oct 27, 2016 at 08:19:27PM +0800, Hanjun Guo wrote:
> I'm trying to using this patch set to solve the functional dependency
> between devices and irqchip, which are both ACPI platform devices.
> irqchip needs to be probed before the devices connecting to them,
> which specifically, it's the mbi-gen support I send out recently:
>
> https://lkml.org/lkml/2016/10/25/453
>
> But I didn't see an example to do so in this patch set, and seems that
> some extra code needs to be added for that purpose, could you give me
> some suggestions for how to do that then I can work on and test against
> your patch set?

If the consumers can detect that there's a consumer on which they depend,
you could call device_link_add() from their ->probe hook.

Generally the earliest point in time when device links can be added is
after device_initialize() has been called for the consumer and device_add()
has been called for the supplier. (At least that's my understanding.)

HTH,

Lukas