Date: Thu, 09 Dec 1999 12:25:33 +0900 From: Seigo Tanimura <tanimura@r.dl.itc.u-tokyo.ac.jp> To: caa@columbus.rr.com Cc: Seigo Tanimura <tanimura@r.dl.itc.u-tokyo.ac.jp> Subject: Re: AWE64 problems Message-ID: <14415.8493.971538.78435L@rina.r.dl.itc.u-tokyo.ac.jp> In-Reply-To: In your message of "Wed, 8 Dec 1999 08:54:15 -0500" <19991208085415.A534@midgard.dhs.org> References: <19991208000746.A1622@midgard.dhs.org> <199912080513.VAA07525@mass.cdrom.com> <19991208085415.A534@midgard.dhs.org>
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[snipped some part]
>> > > On Tue, 7 Dec 1999 23:00:02 +0100 (MET),
>> > > Thomas Schuerger <schuerge@wjpserver.CS.Uni-SB.DE> said:
>> > >
>> > > >> --- sbc.c.orig Mon Dec 6 19:26:31 1999
>> > > >> +++ sbc.c Tue Dec 7 22:15:25 1999
>> > > >> @@ -110,7 +110,7 @@
>> > > >> if (error)
>> > > >> return error;
>> > > >> else
>> > > >> - return -100;
>> > > >> + return -1;
>> > > >> }
>> > > >>
>> > > >> static int
On Wed, 8 Dec 1999 08:54:15 -0500,
"Charles Anderson" <caa@columbus.rr.com> said:
Charles> So then what is -1 and why does it work when -100 doesn't? (I tried it)
sys/kern/subr_bus.c:device_probe_child() receives the value returned
by DEVICE_PROBE(child dev). If the value is zero, no further probes
occur. The device then gets attached in sys/kern/subr_bus.c:
device_probe_and_attach().
If the returned value is less than zero, device_probe_child()
continues probing other possible drivers. For ISA devices, the unknown
driver implemented in sys/isa/isa_common.c is always probed if no
other drivers probe the device successfully. The DEVICE_PROBE() for
any ISA devices with the unknown driver returns -100, so it is, say,
the likelyhood of the unknown driver to the device.
To say the truth, a driver other than the unknown might get to probe
the device in this case, depending on the order to enumerate the
possible drivers in device_probe_child() using {first,next}_matching_driver().
--
Seigo Tanimura <tanimura@r.dl.itc.u-tokyo.ac.jp> <tanimura@freebsd.org>
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