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From: John Baldwin <jhb@freebsd.org>
To: freebsd-current@freebsd.org
Subject: Re: Mis-use of BUS_PASS_ORDER_MIDDLE
Date: Mon, 18 Apr 2016 10:43:17 -0700
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On Monday, April 18, 2016 11:10:12 PM Howard Su wrote:
> I noticed several places there are code like this, especially in some=
 arm
> low level drivers.
> EARLY_DRIVER_MODULE(aw_ccu, simplebus, aw_ccu_driver, aw_ccu_devclass=
,
>     0, 0, BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
>=20
> =E2=80=8BI feel the usage of BUS_PASS_ORDER_MIDDLE is misused. There =
are another
> macro EARLY_DRIVER_MODULE_ORDERED, which take an additional parameter=

> "order". I believe BUS_PASS_ORDER_xxx is used for that parameter.

No, this is actually correct.  The _ORDERED variants actually accept a
SI_ORDER_* value to determine how drivers contained in a single .ko fil=
e
are registered (in particular if you have several drivers in a .ko file=

you typically want the "top-most" driver to attach last so that all the=

other drivers are ready once the actual device is attached).

--=20
John Baldwin