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Date: Mon, 10 May 2010 18:32:37 +0200
From: Ed Schouten <ed@80386.nl>
To: Dmitry Krivenok <krivenok.dmitry@gmail.com>
Message-ID: <20100510163237.GU56080@hoeg.nl>
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Cc: freebsd-hackers@freebsd.org
Subject: Re: Moving from FreeBSD7 to FreeBSD8 (cdev, minor, dev2unit)
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* Dmitry Krivenok <krivenok.dmitry@gmail.com> wrote:
> - int dev_num =3D minor(dev);
> + int dev_num =3D minor(dev2unit(dev));

Almost there. Just remove all calls to unit2minor() and minor2unit() (if
present) and replace minor() with dev2unit():

	int dev_num =3D dev2unit(dev);

But even better, don't use device unit numbers at all. The struct cdev
already provides fields like si_drv1 and si_drv2 that can be used to
store per-device data. Some drivers use constructs like these:

	sc =3D device_get_softc(devclass_get_device(devclass, dev2unit(cdev)));

In those cases the code should just be changed to do something similar
to the following:

	cdev =3D make_dev(....);
	cdev->si_drv1 =3D sc;

Greetings,
--=20
 Ed Schouten <ed@80386.nl>
 WWW: http://80386.nl/

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