Date: Fri, 30 Aug 2002 22:59:52 -0400 (EDT) From: John Baldwin <jhb@FreeBSD.org> To: "M. Warner Losh" <imp@bsdimp.com> Cc: new-bus@FreeBSD.ORG Subject: Re: bus_generic_probe() is wrong I think Message-ID: <XFMail.20020830225952.jhb@FreeBSD.org> In-Reply-To: <20020830.203228.35798916.imp@bsdimp.com>
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On 31-Aug-2002 M. Warner Losh wrote: > 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. Pretty much what I was saying. I have an atsys(4) driver btw that apm and nexus_pcib are now descendants of and only gets attached if the acpi identify fails in the jhb_acpipci p4 branch. -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-new-bus" in the body of the message
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