Re: [PATCH v4 2/4] x86/irq: Fall back to irq_chip_retrigger_hierarchy() in fixup_irqs()

[sashiko-bot@kernel.org]

> 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@kernel.org>
> Reviewed-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
> Reviewed-by: Thomas Gleixner <tglx@kernel.org>
> Reviewed-by: Michael Kelley <mhklinux@outlook.com>
> Signed-off-by: Naman Jain <namjain@linux.microsoft.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260909064448.1004-1-namjain@linux.microsoft.com?part=2