sys_irq_enable

API definition

Rust UAPI for irq_enable syscall
mod uapi {
   fn irq_enable(irq: u16) -> Status
 }
C UAPI for irq_enable syscall
enum Status sys_irq_enable(uint16_t IRQn);

Usage

Enable (unmask) given IRQ line at IRQ controller level.

Note

the controller assignation is not yet supported with this API, and would require a modification to support this

This syscall is made in order to allow userspace driver to enable a given IRQ once the device is properly configured.

This requires the interrupt line to be owned by a device of the given task.

The kernel do not modify the IRQ enable flag of any devices here, but only unmasks the IRQ line in the main interrupt controller. This means that an interrupt may rise as soon as the kernel unmask the interrupt, pushing an interrupt event in the task’s input queue just after the syscall execution. The userspace driver is responsible for (un)masking the interrupt-enable flag at device level.
enable given IRQ of an owned device
1// configure the device (and device-relative IRQ config)
2// [...]
3if (sys_irq_enable(myIRQn) != STATUS_OK) {
4      // [...]
5}

Required capability

at least one CAP_DEV_xxx capa is required, as the IRQ enabling is linked to a given device.

Return values

STATUS_INVALID if the IRQ is not owned or do not exists

STATUS_DENIED if the task do not hold any DEV capability

STATUS_OK