Re: [PATCH 4/5] i2c: core: Move ACPI gpio IRQ handling into i2c_acpi_get_irq

Charles Keepax
2019-05-22T08:19:47Z

On Tue, May 21, 2019 at 08:27:26PM +0300, Andy Shevchenko wrote:
> On Tue, May 21, 2019 at 04:05:01PM +0100, Charles Keepax wrote:
> > It makes sense to contain all the ACPI IRQ handling in a single helper
> > function.
>
> > Note that this one is somewhat interesting, it seems the search
> > through the resource list is done against the companion device
> > of the adapter but the GPIO search is done against the companion
> > device of the client. It feels to me like these really should
> > be done on the same device, and certainly this is what SPI
> > does (both against the equivalent of the adapter). Perhaps
> > someone with more ACPI knowledge than myself could comment?
>
> It would be interesting to see the path how you come to this conclusion.
>

Apologies but I am not sure which conclusion you are referencing.
Assuming it is them being called with different acpi_device's.
It is perhaps me misunderstanding things but it looks like
i2c_acpi_get_info implies the adev should correspond to the
adapter. Where as acpi_dev_gpio_irq_get is called with the result
of ACPI_COMPANION(dev) where dev is client->dev.

> > acpi_dev_free_resource_list(&resource_list);
> >
> > + if (*irq < 0)
> > + *irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(&client->dev), 0);
>
> I think adev here is what we may use here.
>

Indeed that is what I would have expected as well, I will update
the code to do so and hopefully any issues will come out in
testing.

> You may put assert here and see if it happens when you test your series.
>

Alas I don't have a good way to test this series, they come out
of some additional work Wolfram wanted based on some issues
caused by a device tree fix I made a while back.

Thanks,
Charles