Re: [PATCH v2 2/7] ACPI / LPSS: allow to use specific PM domain during ->probe()

Jarkko Nikula
2015-12-04T13:06:35Z

On 12/03/2015 09:29 PM, Shevchenko, Andriy wrote:
> I briefly checked this for DMA issue. It will not help anyhow, so we
> *have to* move a power domain assignment to the BIND stage.
>
> For I2C and rest LPSS devices this might help (though didn't look
> deeply). My understanding that we assign those callbacks in the LPSS
> custom PM domain and call them explicitly in acpi_lpss.c.
>
> The code will be the same as we are using now to bring device from
> runtime suspend resume. This means whenever we call probe for e.g. I2C
> we end up in a sequence similar to:
> pm_runtime_resume(I2C);
> ->probe(I2C);
> pm_runtime_suspend(I2C);
>
> I will try to mock up this and check if it will work, though have no
> idea what to do if I2C during probe calls pm_runtime_forbid().
>
> Jarkko, what do you think?
>
I suppose device core will handle it. If the runtime PM is forbidden or
not initialized at all the device shouldn't idle.

--
Jarkko