Many thanks, I have given this a try today but unfortunately can't locate the specific Target & Vector combination. Here's what I saw:
$ uname -r 4.20.0-1-generic $ dmesg | tail [ 167.279809] do_IRQ: 1.35 No irq handler for vector # grep 35 /sys/kernel/debug/irq/irqs/* /sys/kernel/debug/irq/irqs/125: Vector: 35 /sys/kernel/debug/irq/irqs/126: Vector: 35 # cat /sys/kernel/debug/irq/irqs/125 handler: handle_edge_irq device: 0000:00:02.0 status: 0x00000000 istate: 0x00000000 ddepth: 0 wdepth: 0 dstate: 0x01401300 IRQD_ACTIVATED IRQD_IRQ_STARTED IRQD_SINGLE_TARGET IRQD_AFFINITY_SET IRQD_SETAFFINITY_PENDING node: -1 affinity: 0-3 effectiv: 2 pending: 1 domain: PCI-MSI-3 hwirq: 0x8000 chip: PCI-MSI flags: 0x30 IRQCHIP_SKIP_SET_WAKE IRQCHIP_ONESHOT_SAFE parent: domain: VECTOR hwirq: 0x7d chip: APIC flags: 0x0 Vector: 35 Target: 2 move_in_progress: 0 is_managed: 0 can_reserve: 0 has_reserved: 0 cleanup_pending: 0 # cat /sys/kernel/debug/irq/irqs/126 handler: handle_edge_irq device: 0000:00:16.0 status: 0x00000000 istate: 0x00000000 ddepth: 0 wdepth: 0 dstate: 0x01400200 IRQD_ACTIVATED IRQD_IRQ_STARTED IRQD_SINGLE_TARGET node: -1 affinity: 0-3 effectiv: 3 pending: domain: PCI-MSI-3 hwirq: 0x58000 chip: PCI-MSI flags: 0x30 IRQCHIP_SKIP_SET_WAKE IRQCHIP_ONESHOT_SAFE parent: domain: VECTOR hwirq: 0x7e chip: APIC flags: 0x0 Vector: 35 Target: 3 move_in_progress: 0 is_managed: 0 can_reserve: 0 has_reserved: 0 cleanup_pending: 0 Some suggestions from friends with experience in this matter run along the lines of attempting to boot with an ACPI_OSI kernel parameter given the bugs reported within my dmesg, shall I give that a try? Alternatively, I am game for any further suggestions! :) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1781016 Title: Slow flood of do_IRQ: No irq for vector To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1781016/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs