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Date:   Wed, 26 May 2021 20:18:10 +0200
From:   Lukas Wunner <lukas@wunner.de>
To:     Lambert Wang <lambert.q.wang@gmail.com>
Cc:     Krzysztof Wilczy??ski <kw@linux.com>,
        Bjorn Helgaas <bhelgaas@google.com>, linux-pci@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] pci: add pci_dev_is_alive API
Message-ID: <20210526181810.GA13052@wunner.de>
References: <20210525125925.112306-1-lambert.q.wang@gmail.com>
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 <CAATamay8WTiJnB=5OLYdFTqVUcRF9LarN6_1Eej3QUgFzWRnkA@mail.gmail.com>
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On Wed, May 26, 2021 at 02:12:38PM +0800, Lambert Wang wrote:
> The user is our new PCI driver under development for WWAN devices .
> Surprise removal could happen under multiple circumstances.
> e.g. Exception, Link Failure, etc.
> 
> We wanted this API to detect surprise removal or check device recovery
> when AER and Hotplug are disabled.

You may want to take a look at pci_dev_is_disconnected().

Be aware of its limitations, which Bjorn has already pointed out
and which are discussed in more detail under the following link
in the "Surprise removal" section:

https://lwn.net/Articles/767885/

Thanks,

Lukas