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

[Naman Jain]

On 9/22/2026 2:31 AM, Michael Kelley wrote:

From: Naman Jain <namj...@linux.microsoft.com> 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"?

Thanks for catching this Michael, it was a miss on my part.

Regards,
Naman

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 <t...@kernel.org>
Reviewed-by: Shradha Gupta <shradhagu...@linux.microsoft.com>
Reviewed-by: Thomas Gleixner <t...@kernel.org>
Signed-off-by: Naman Jain <namj...@linux.microsoft.com>
---
  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