Hi Geert,
On 16/11/15 10:48, Geert Uytterhoeven wrote:
> On Mon, Nov 16, 2015 at 11:34 AM, Jon Hunter <jonath...@nvidia.com> wrote:
[snip]
>>> Handling it automatically needs more bookkeeping than a simple reference
>>> count.
>>
>> So what would you suggest? Adding a pm_runtime_register_irq() API that
>> would register an IRQ with the device that you want RPM to handle? Not
>> sure if there is a better/easier way to handle this.
>
> The irqchip needs to keep track how many times request_irq() has been
> called, cfr. your suggestion above.
>
> On the other side, the system needs to keep track how many times request_irq()
> has been called for each irqchip, so it can subtract those numbers from the
> irqchip's counters during suspend of the device, and re-add them during
> resume.
> So we need at least a "struct device *" parameter for request_irq().
> devm_request_irq() already has that, but not all drivers use that.
Yes that would make sense. However, I am wondering if the
syscore suspend/resume operators could be used here to do something
like ...
pm_runtime_disable(dev);
if (!pm_runtime_status_suspended(dev))
chip->irq_runtime_suspend(data);
> However, I think this should be looked at into the context of "[RFD]
> Functional dependencies between devices".
> https://lwn.net/Articles/662205/
> https://lkml.org/lkml/2015/10/27/388
>
> There can be other dependencies than interrupts between devices.
> All functions using dependencies need a "struct device *" parameter to
> record information.
Yes I like the sound of that. That would be ideal. However, I am
guessing that that is a way off at the moment ...
Cheers
Jon
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