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Date:      Fri, 30 Aug 2002 20:32:28 -0600 (MDT)
From:      "M. Warner Losh" <imp@bsdimp.com>
To:        jhb@FreeBSD.ORG
Cc:        new-bus@FreeBSD.ORG
Subject:   Re: bus_generic_probe() is wrong I think
Message-ID:  <20020830.203228.35798916.imp@bsdimp.com>
In-Reply-To: <XFMail.20020830133542.jhb@FreeBSD.org>
References:  <XFMail.20020830133542.jhb@FreeBSD.org>

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In message: <XFMail.20020830133542.jhb@FreeBSD.org>
            John Baldwin <jhb@FreeBSD.ORG> writes:
: If we are going to support having multiple driver's for a given device
: which is a bus (like we do now for PCI busses and like I am doing for
: this concept of a system buson i386) then I think that bus devices do
: not need to go identify child devices until after they have won the
: probe and are being attached.  Thus, I'm ending up calling
: bus_generic_probe() in my attach routines instead of my probe routines.
: Does this make sense or am I missing something?  I at least have to do
: this in the system bus case here for the same reasons that when I added
: another PCI bus driver, I had to change the PCI drivers to add children
: devices (equivalent of doing an identify) during attach() time and not
: during probe() time.

A more fundamental question is why bus_generic_probe() does the child
attach/probe?  In the probe routine, there's no guarantee that the
bus will actually attach at some later point.  Shouldn't that be in a
bus_generic_attach() routine?  The probe should just say 'is this bus
here' and the attach should make it possible to then probe the
children after a successful attach.

Warner

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