Re: [PATCH v2 3/3] x86/irq, iommu/amd, PCI: Drop redundant irq_retrigger inits

On 8/18/2026 10:40 AM, Michael Kelley wrote:

From: Naman Jain <redacted> Sent: Monday, August 10, 2026 2:07 AM

quoted

With fixup_irqs() now using irq_chip_retrigger_hierarchy() and the generic
resend path (try_retrigger()) already falling back to it, installing
irq_chip_retrigger_hierarchy() 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.
msi_set_affinity() is the only site that invoked the outermost chip's
irq_retrigger() directly. Convert it to irq_chip_retrigger_hierarchy() so
the x86_init_dev_msi_info() initialization can be dropped as well.

No functional change intended.

Suggested-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Shradha Gupta <redacted>
Signed-off-by: Naman Jain <redacted>
---
  arch/x86/kernel/apic/io_apic.c      | 2 --
  arch/x86/kernel/apic/msi.c          | 4 +---
  arch/x86/kernel/hpet.c              | 1 -
  drivers/iommu/amd/init.c            | 1 -
  drivers/pci/controller/pci-hyperv.c | 1 -
  5 files changed, 1 insertion(+), 8 deletions(-)

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 66bc5d3e79db3..aad2f15eb2176 100644
--- a/arch/x86/kernel/apic/msi.c
+++ b/arch/x86/kernel/apic/msi.c

@@ -137,7 +137,7 @@ msi_set_affinity(struct irq_data *irqd, const struct cpumask *mask, bool force)
  	 * IRR.
  	 */
  	if (lapic_vector_set_in_irr(cfg->vector))
-		irq_data_get_irq_chip(irqd)->irq_retrigger(irqd);
+		irq_chip_retrigger_hierarchy(irqd);

Again, this will miss the outermost chip's retrigger function if it
is set to something custom.

Michael

In case we all agree to adding a fallback in previous patch, I am 
afraid, we will have to add it here as well.

Regards,
Naman

quoted

  	return ret;
  }

@@ -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 ea3377e61aa5c..0c362e86a09d9 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c

@@ -2468,7 +2468,6 @@ 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