Re: [PATCH] surface: aggregator: propagate -EPROBE_DEFER from ssam_irq_setup()

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

On Mon, 26 Oct 2026, Chris Simpson wrote:

> Hi Ilpo,
> 
> > Are there some legimate cases where error other than -EDEFER_PROBE should
> > end up into this else like it previously did?
> 
> Two corrections to my earlier mail first. The Surface Pro 9 here is
> Alder Lake (i7-1255U), not Tiger Lake; its GPIO controller, INTC1055,
> is handled by pinctrl-tigerlake, which is where my mix-up came from.
> And "follows Ilpo's comment" was my misreading of your review: the
> gpiod_get_optional() idea was mine, sorry for attributing it to you
> (v2's "Suggested by Ilpo" comes from that too).

Np. The end result seems better even if there was misread which triggered 
that. At least sometimes misreading ends up being useful. :-)

--
 i.

> On the question, I couldn't find such a case:
> 
> - DT: microsoft,surface-sam.yaml requires "interrupts" and has
>   additionalProperties: false, and the in-tree DTS files
>   (sc8280xp-microsoft-arcata, x1e80100-microsoft-romulus,
>   x1-microsoft-denali, x1p42100-microsoft-sp12in) all use
>   interrupts-extended. So on DT gpiod_get() returns -ENOENT, which
>   gpiod_get_optional() turns into NULL, and v2 still takes the
>   fwnode_irq_get() path.
> 
> - ACPI: fwnode_irq_get() ends up in acpi_irq_get(), which only looks at
>   Interrupt()/IRQ() resources, not GpioInt(). On the Pro 9 (UEFI
>   22.107.143) the MSHW0084 _CRS has UartSerialBusV2 plus GpioInt and
>   GpioIo on pin 174 of INTC1055, and no Interrupt() or IRQ(), and the
>   Surface Laptop 4 tables in linux-surface#2219 have the same layout.
>   So on these two machines the fallback can only turn -EPROBE_DEFER, or
>   a real GPIO error, into -EINVAL; for -EPROBE_DEFER that is the probe
>   failure v2 fixes.
> 
> What I can't tell is whether Konrad had another case in mind, or whether
> some other Surface model has a plain Interrupt() there; I've only looked
> at these two. I'm happy to test any variant on the Pro 9. As before, I
> did the analysis with Claude Code.
> 
> Chris Simpson
>