On Tue, Apr 07, 2026 at 08:39:03AM -0400, Andrew Stellman wrote:
> vp_interrupt() unconditionally returns the result of
> vp_vring_interrupt(). When a config-change interrupt fires but no vring
> activity is pending, vp_vring_interrupt() returns IRQ_NONE — even
> though the interrupt was legitimately handled by vp_config_changed().
> Over time this causes the IRQ subsystem to flag the line as spurious.
>
> Track the return value explicitly: set ret to IRQ_HANDLED when the
> config-change bit is set, OR it with the vring result, and return the
> combined value.
>
> Signed-off-by: Andrew Stellman <[email protected]>
Fixes tag?
> ---
> drivers/virtio/virtio_pci_common.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/virtio/virtio_pci_common.c
> b/drivers/virtio/virtio_pci_common.c
> index 0b9d66b..1d1ab02 100644
> --- a/drivers/virtio/virtio_pci_common.c
> +++ b/drivers/virtio/virtio_pci_common.c
> @@ -106,6 +106,7 @@ static irqreturn_t vp_vring_interrupt(int irq, void
> *opaque)
> static irqreturn_t vp_interrupt(int irq, void *opaque)
> {
> struct virtio_pci_device *vp_dev = opaque;
> + irqreturn_t ret = IRQ_NONE;
> u8 isr;
>
> /* reading the ISR has the effect of also clearing it so it's very
> @@ -117,10 +118,15 @@ static irqreturn_t vp_interrupt(int irq, void *opaque)
> return IRQ_NONE;
>
> /* Configuration change? Tell driver if it wants to know. */
> - if (isr & VIRTIO_PCI_ISR_CONFIG)
> + if (isr & VIRTIO_PCI_ISR_CONFIG) {
> vp_config_changed(irq, opaque);
> + ret = IRQ_HANDLED;
> + }
>
> - return vp_vring_interrupt(irq, opaque);
> + if (vp_vring_interrupt(irq, opaque) == IRQ_HANDLED)
> + ret = IRQ_HANDLED;
> +
> + return ret;
> }
>
> static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
> --
> 2.34.1
