Re: [PATCH v3 2/3] x86/irq: Fall back to irq_chip_retrigger_hierarchy() in fixup_irqs()

[Thomas Gleixner]

On Mon, Sep 07 2026 at 06:51, Naman Jain wrote:
> fixup_irqs() re-injects a pending interrupt on its new target CPU by
> looking at the outermost domain chip and invoking its irq_retrigger()
> callback directly. When the outermost chip does not implement
> irq_retrigger(), the pending interrupt is silently dropped, which can
> lead to lost interrupts on CPU hot-unplug.
>
> Keep calling the outermost chip's irq_retrigger() when it is present,
> but fall back to irq_chip_retrigger_hierarchy() otherwise, which walks
> up the interrupt hierarchy until it finds a chip that implements
> irq_retrigger().
>
> While at it, use a scoped guard for desc->lock. VECTOR_RETRIGGERED is
> now set only when the retrigger succeeds instead of unconditionally,
> which is harmless today since apic_retrigger_irq() always returns 1.
>
> Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxx>
> Reviewed-by: Shradha Gupta <shradhagupta@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Naman Jain <namjain@xxxxxxxxxxxxxxxxxxx>

Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxx>