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

[Naman Jain <namjain@linux.microsoft.com>]

On 9/22/2026 2:31 AM, Michael Kelley wrote:
> From: Naman Jain <namjain@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 <tglx@kernel.org>
>> Reviewed-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
>> Reviewed-by: Thomas Gleixner <tglx@kernel.org>
>> Signed-off-by: Naman Jain <namjain@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
>>
>