Date: Wed, 7 Jun 2000 19:57:50 +1000 (EST) From: Bruce Evans <bde@zeta.org.au> To: Leonid Lukiyanets <stalwar78@hotmail.com> Cc: freebsd-bugs@FreeBSD.ORG, dfr@FreeBSD.ORG, yokota@FreeBSD.ORG Subject: Re: sio number cannot be over 25??? Message-ID: <Pine.BSF.4.21.0006071915470.299-100000@besplex.bde.org> In-Reply-To: <20000603052347.26386.qmail@hotmail.com>
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On Sat, 3 Jun 2000, Leonid Lukiyanets wrote:
> I am upgrading from 3.4 to 4.0 version.
> In my system 3 Moxa multiport adapters are used.
> So my usual setup is sio0 for com1, sio25 for com2 and sio1 to sio 24
> assigned to multiports.
> Everything worked perfectly fine with FreeBSD 3.4, but when I tried to
> compile such a kernel under 4.0 version my keyboard stopped working after
> reboot.
> After numerous kernel experiments I have discovered that when I assign sio
> with number over 24 to com2 the system fails to load keyboard driver.
Allocation of unit numbers is quite broken in 4.0 and -current. It happens
to work for the normal allocation order { 0, 1, 2, ... }, but your
configuration gives the order { 0, 25, 1, 2, ... } for sio. When the unit
number for sio25 is allocated, only enough space for 8 units is actually
allocated. The short amount of space happens to be allocated a bit below
the resource entry for atkbdc's ports, and the assignment to
dc->devices[dev->unit] happens to corrupt the `type' member in this entry,
so the first call to atkbdc_probe() fails because the ports can't be
found. Fortunately, the corruption with my configuration was in the
same place as you reported, so it was easy to reproduce the bug.
Fix:
diff -c2 subr_bus.c~ subr_bus.c
*** subr_bus.c~ Sun May 28 16:05:23 2000
--- subr_bus.c Wed Jun 7 18:54:51 2000
***************
*** 377,382 ****
int newsize;
! newsize = (dc->maxunit ? 2 * dc->maxunit
! : MINALLOCSIZE / sizeof(device_t));
newlist = malloc(sizeof(device_t) * newsize, M_BUS, M_NOWAIT);
if (!newlist)
--- 377,381 ----
int newsize;
! newsize = roundup((unit + 1), MINALLOCSIZE / sizeof(device_t));
newlist = malloc(sizeof(device_t) * newsize, M_BUS, M_NOWAIT);
if (!newlist)
I didn't bother rounding up the allocation size to a power of 2 like
the old code attempted.
Minor bugs found while investigating this:
atkbdc_probe() is called later for the PNP entry that normally causes the
warning "unknown: <PNP0303> can't assign resources" on an Abit BP6
motherboard. When the initial probe fails due to the bug, the second
probe succeeds, so the message
"atkbdc1: <Keyboard controller (i8042)> at port 0x60,0x64 irq 1 on isa0"
is printed instead of the warning, but the unit number is bogus, and
atkbdc_attach() fails and the message:
"device_probe_and_attach: atkbdc1 attach returned 12"
is printed. Here "12" is ENOMEM, which is returned by atkbdc_attach()
when atkbdc_get_softc() fails, but the error has nothing to do with
memory allocation failure.
Bruce
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