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From:   Bharat Kumar Gogada <bharatku@xilinx.com>
To:     "linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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        "hch@lst.de" <hch@lst.de>, "axboe@fb.com" <axboe@fb.com>
Subject: RE: NVMe Poll CQ on timeout
Thread-Topic: NVMe Poll CQ on timeout
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Date:   Mon, 7 May 2018 06:57:54 +0000
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Hi,

Does anyone have any inputs ?

Regards,
Bharat

> Hi,
>=20
> 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;
>         }
>=20
> 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 ?
>=20
> Regards,
> Bharat
>=20