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From:   Rajat Jain <rajatja@google.com>
Date:   Mon, 26 Apr 2021 12:47:59 -0700
Message-ID: <CACK8Z6E=JwkzyF8Ph=F_ATzVAxNWB5TL-xKfS12Y87nmaQTbFg@mail.gmail.com>
Subject: Re: [PATCH v2 2/2] pci: Support "removable" attribute for PCI devices
To:     David Laight <David.Laight@aculab.com>
Cc:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Oliver Neukum <oneukum@suse.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Alan Stern <stern@rowland.harvard.edu>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux PCI <linux-pci@vger.kernel.org>,
        "open list:ULTRA-WIDEBAND (UWB) SUBSYSTEM:" 
        <linux-usb@vger.kernel.org>, Bjorn Helgaas <helgaas@kernel.org>,
        Rajat Jain <rajatxjain@gmail.com>,
        Jesse Barnes <jsbarnes@google.com>,
        Dmitry Torokhov <dtor@google.com>
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On Mon, Apr 26, 2021 at 6:01 AM David Laight <David.Laight@aculab.com> wrote:
>
> From: Rafael J. Wysocki
> > Sent: 26 April 2021 12:49
> >
> > On Mon, Apr 26, 2021 at 11:17 AM Oliver Neukum <oneukum@suse.com> wrote:
> > >
> > > Am Freitag, den 23.04.2021, 19:16 -0700 schrieb Rajat Jain:
> > > > Export the already available info, to the userspace via the
> > > > device core, so that userspace can implement whatever policies it
> > > > wants to, for external removable devices.
> > >
> > > Hi,
> > >
> > > is there a way to tell apart whether a device can undergo regular
> > > surprise removal?
> >
> > PCI devices located under a removable parent can undergo surprise
> > removal.  The ones on a Thunderbolt chain too.
> >
> > > Do we want that?
> >
> > Do you mean surprise removal?  Yes, we do.
>
> Always been true - think of cardbus (PCI pcmcia) cards with
> PCI bridges to external PCI expansion chassis containing
> additional PCI slots.
> The cardbus card is hot removable.

Hi Oliver / Folks, please let me know if there is a suggestion for me
here, or if there is still a question for me to answer.

Thanks,

Rajat

PS: To give some background about this change, we'd like to implement
some policies around disabling user plugged devices when a user logs
out, and collect statistics around use of such devices.

>
>         David
>
> -
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