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SubjectRe: [PATCH] PCI: hv: Do not wait forever on a device that has disappeared
On Thu, May 24, 2018 at 12:12 AM, Dexuan Cui <decui@microsoft.com> wrote:
>
> Before the guest finishes the device initialization, the device can be
> removed anytime by the host, and after that the host won't respond to
> the guest's request, so the guest should be prepared to handle this
> case.

> + while (true) {
> + if (hdev->channel->rescind) {
> + dev_warn_once(&hdev->device, "The device is gone.\n");
> + return -ENODEV;
> + }
> +
> + if (wait_for_completion_timeout(comp, HZ / 10))
> + break;
> + }

Infinite loops are usually a red flags.

What's wrong with simple:

do {
...
} while (wait_...(...) == 0);

?

> + if (!ret)
> + ret = wait_for_response(hdev, &comp);

Better to use well established patterns, i.e.

if (ret)
return ret;

> + if (!ret)
> + ret = wait_for_response(hdev, &comp_pkt.host_event);

Here it looks okay on the first glance, but better to think about it
again and refactor.

--
With Best Regards,
Andy Shevchenko

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