Speaker
Description
In ACPI based system,devices can be created out of ACPI static tables entries (eg ARM64 IORT, GTDT). For those devices, the GSI HW interrupt number is retrieved by reading table specific fields that are different for different static tables. Devices created out of static ACPI tables might be created before the interrupt controller drivers their GSI interrupt is routed to is probed, which means that when the platform device is created the IRQ domain that should be used to map the GSI into a virtual IRQ may not be registered yet.
This leaves us with two issues:
- device drivers for devices created out of static tables can probe only after the interrupt controller driver their IRQ is routed to has probed
- In order to map the virtual IRQ for those devices at device driver probe time, the static table GSI HW IRQ number must be stashed somewhere in the device object so that it can be retrieved and mapped to a virtual IRQ when the device driver is actually probed
Prototyping for this solution is under way and a solution for ACPI namespace devices was already posted[1] (but that can't solve the problem for devices that are created out of static table entries).
This session would help define a way forward.
[1] https://lore.kernel.org/lkml/20260505-gic-v5-acpi-iwb-probe-deferral-v1-0-b37b85998362@kernel.org/