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Date: Sat, 4 Nov 2017 18:05:48 +0100
From: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andrey Smirnov <andrew.smirnov@gmail.com>,
        linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org,
        Rob Herring <robh@kernel.org>, cphealy@gmail.com,
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        Andy Shevchenko <andy.shevchenko@gmail.com>,
        Johan Hovold <johan@kernel.org>
Subject: Re: [PATCH v10 1/5] serdev: Make .remove in struct
 serdev_device_driver optional
Message-ID: <20171104170548.vkkgp363k2piyufx@earth>
References: <20171031163656.24552-1-andrew.smirnov@gmail.com>
 <20171031163656.24552-2-andrew.smirnov@gmail.com>
 <20171104112431.GA24583@kroah.com>
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Hi Greg,

On Sat, Nov 04, 2017 at 12:24:31PM +0100, Greg Kroah-Hartman wrote:
> On Tue, Oct 31, 2017 at 09:36:52AM -0700, Andrey Smirnov wrote:
> > Using devres infrastructure it is possible to write a serdev driver
> > that doesn't have any code that needs to be called as a part of
> > .remove. Add code to make .remove optional.
>=20
> What about manual unbind from userspace through sysfs?  You need to have
> a remove function.  All drivers need that, to not have it is pretty lazy =
:)

Resources,that have been requested via devres are free'd by the
devres framework after the driver specific remove function. This
also works for manual unbind.

If *all* driver resources are allocated using devres, you will end
up with an empty remove function. In that case it makes sense to
remove it completly. This is what quite a few (mainline) i2c and
spi drivers actually do.

-- Sebastian

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