NVMe Poll CQ on timeout

[Bharat Kumar Gogada]

Hi,

We are testing NVMe cards on ARM64 platform, the card uses legacy interrupts.
Intermittently we are hitting following case in drivers/nvme/host/pci.c
       /*
         * Did we miss an interrupt?
         */
        if (__nvme_poll(nvmeq, req->tag)) {
                dev_warn(dev->ctrl.device,
                         "I/O %d QID %d timeout, completion polled\n",
                         req->tag, nvmeq->qid);
                return BLK_EH_HANDLED;
        }

Can anyone tell when does nvme_timeout gets invoked ?
What does "Did we miss an interrupt mean" ? Does it mean host missing
to service a interrupt raised by EP card ?

Regards,
Bharat