RE: [PATCH v5 4/4] x86/irq, iommu/amd, x86/hyperv, PCI: Drop redundant irq_retrigger inits

[Michael Kelley]

From: Naman Jain <namjain@xxxxxxxxxxxxxxxxxxx> Sent: Monday, September 14, 2026 4:19 AM
> 
> With fixup_irqs(), msi_set_affinity() and the generic resend path
> (try_retrigger()) now all falling back to irq_chip_retrigger_hierarchy(),

The "falling back" terminology is not accurate in this version of the
patch set.  Perhaps "all now calling irq_chip_retrigger_hierarchy() directly"?

> installing it as the irq_retrigger() callback on the outermost domain chips
> is no longer required. The hierarchy walk reaches the x86 vector domain's
> apic_retrigger_irq() for all of these stacked domain chips.
> 
> Remove the now redundant irq_retrigger() initializations from the outermost
> domain interrupt chips, including the Hyper-V root partition PCI/MSI chip.
> 
> No functional change intended.
> 
> Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxx>
> Reviewed-by: Shradha Gupta <shradhagupta@xxxxxxxxxxxxxxxxxxx>
> Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxx>
> Signed-off-by: Naman Jain <namjain@xxxxxxxxxxxxxxxxxxx>
> ---
>  arch/x86/hyperv/irqdomain.c         | 1 -
>  arch/x86/kernel/apic/io_apic.c      | 2 --
>  arch/x86/kernel/apic/msi.c          | 2 --
>  arch/x86/kernel/hpet.c              | 1 -
>  drivers/iommu/amd/init.c            | 1 -
>  drivers/pci/controller/pci-hyperv.c | 1 -
>  6 files changed, 8 deletions(-)
> 
> diff --git a/arch/x86/hyperv/irqdomain.c b/arch/x86/hyperv/irqdomain.c
> index 6d790636c8b95..b3ad50a874dca 100644
> --- a/arch/x86/hyperv/irqdomain.c
> +++ b/arch/x86/hyperv/irqdomain.c
> @@ -316,7 +316,6 @@ static bool hv_init_dev_msi_info(struct device *dev, struct
> irq_domain *domain,
>  		return false;
> 
>  	chip->flags |= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MOVE_DEFERRED;
> -	chip->irq_retrigger = irq_chip_retrigger_hierarchy;
> 
>  	info->ops->msi_prepare = pci_msi_prepare;
> 
> diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
> index 7d7175d012288..18f49a251f23b 100644
> --- a/arch/x86/kernel/apic/io_apic.c
> +++ b/arch/x86/kernel/apic/io_apic.c
> @@ -1857,7 +1857,6 @@ static struct irq_chip ioapic_chip __read_mostly = {
>  	.irq_ack		= irq_chip_ack_parent,
>  	.irq_eoi		= ioapic_ack_level,
>  	.irq_set_affinity	= ioapic_set_affinity,
> -	.irq_retrigger		= irq_chip_retrigger_hierarchy,
>  	.irq_get_irqchip_state	= ioapic_irq_get_chip_state,
>  	.flags			= IRQCHIP_SKIP_SET_WAKE |
> IRQCHIP_MOVE_DEFERRED |
>  				  IRQCHIP_AFFINITY_PRE_STARTUP,
> @@ -1871,7 +1870,6 @@ static struct irq_chip ioapic_ir_chip __read_mostly = {
>  	.irq_ack		= irq_chip_ack_parent,
>  	.irq_eoi		= ioapic_ir_ack_level,
>  	.irq_set_affinity	= ioapic_set_affinity,
> -	.irq_retrigger		= irq_chip_retrigger_hierarchy,
>  	.irq_get_irqchip_state	= ioapic_irq_get_chip_state,
>  	.flags			= IRQCHIP_SKIP_SET_WAKE |
>  				  IRQCHIP_AFFINITY_PRE_STARTUP,
> diff --git a/arch/x86/kernel/apic/msi.c b/arch/x86/kernel/apic/msi.c
> index 9160227b9b32a..aad2f15eb2176 100644
> --- a/arch/x86/kernel/apic/msi.c
> +++ b/arch/x86/kernel/apic/msi.c
> @@ -246,7 +246,6 @@ static bool x86_init_dev_msi_info(struct device *dev, struct
> irq_domain *domain,
>  	info->ops->msi_prepare		= x86_msi_prepare;
> 
>  	info->chip->irq_ack		= irq_chip_ack_parent;
> -	info->chip->irq_retrigger	= irq_chip_retrigger_hierarchy;
>  	info->chip->flags		|= IRQCHIP_SKIP_SET_WAKE |
>  					   IRQCHIP_AFFINITY_PRE_STARTUP;
> 
> @@ -313,7 +312,6 @@ static struct irq_chip dmar_msi_controller = {
>  	.irq_mask		= dmar_msi_mask,
>  	.irq_ack		= irq_chip_ack_parent,
>  	.irq_set_affinity	= msi_domain_set_affinity,
> -	.irq_retrigger		= irq_chip_retrigger_hierarchy,
>  	.irq_compose_msi_msg	= dmar_msi_compose_msg,
>  	.irq_write_msi_msg	= dmar_msi_write_msg,
>  	.flags			= IRQCHIP_SKIP_SET_WAKE |
> IRQCHIP_MOVE_DEFERRED |
> diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
> index 8dc7b710e1250..2bb7a6f466af3 100644
> --- a/arch/x86/kernel/hpet.c
> +++ b/arch/x86/kernel/hpet.c
> @@ -509,7 +509,6 @@ static struct irq_chip hpet_msi_controller __ro_after_init = {
>  	.irq_mask = hpet_msi_mask,
>  	.irq_ack = irq_chip_ack_parent,
>  	.irq_set_affinity = msi_domain_set_affinity,
> -	.irq_retrigger = irq_chip_retrigger_hierarchy,
>  	.irq_write_msi_msg = hpet_msi_write_msg,
>  	.flags = IRQCHIP_SKIP_SET_WAKE | IRQCHIP_AFFINITY_PRE_STARTUP,
>  };
> diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
> index edcc187b8f14f..bc3da5b0578eb 100644
> --- a/drivers/iommu/amd/init.c
> +++ b/drivers/iommu/amd/init.c
> @@ -2477,7 +2477,6 @@ static struct irq_chip intcapxt_controller = {
>  	.irq_unmask		= intcapxt_unmask_irq,
>  	.irq_mask		= intcapxt_mask_irq,
>  	.irq_ack		= irq_chip_ack_parent,
> -	.irq_retrigger		= irq_chip_retrigger_hierarchy,
>  	.irq_set_affinity       = intcapxt_set_affinity,
>  	.irq_set_wake		= intcapxt_set_wake,
>  	.flags			= IRQCHIP_MASK_ON_SUSPEND |
> IRQCHIP_MOVE_DEFERRED,
> diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> index 89816a2bd7cd3..cfc8fa403dad6 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -2119,7 +2119,6 @@ static bool hv_pcie_init_dev_msi_info(struct device *dev,
> struct irq_domain *dom
>  	info->ops->msi_prepare = hv_msi_prepare;
> 
>  	chip->irq_set_affinity = irq_chip_set_affinity_parent;
> -	chip->irq_retrigger = irq_chip_retrigger_hierarchy;
> 
>  	if (IS_ENABLED(CONFIG_X86))
>  		chip->flags |= IRQCHIP_MOVE_DEFERRED;
> --
> 2.43.0
>