Re: port-amd64/39630: New ipmi(4) attachment code triggers kernel panic

[Matthias Scheler <tron%zhadum.org.uk@localhost>]

        Hello,

I've added the following debugging output:

Index: ipmi.c
===================================================================
RCS file: /cvsroot/src/sys/arch/x86/x86/ipmi.c,v
retrieving revision 1.21
diff -u -r1.21 ipmi.c
--- ipmi.c      30 Oct 2008 20:28:02 -0000      1.21
+++ ipmi.c      4 Nov 2008 17:53:45 -0000
@@ -292,19 +292,23 @@
        struct ipmi_softc       *sc = arg;
        struct ipmi_bmc_args    *a = sc->sc_iowait_args;
 
+       aprint_normal("_bmc_io_wait: sc=%p, a=%p\n", sc, a);
        *a->v = bmc_read(sc, a->offset);
        if ((*a->v & a->mask) == a->value) {
+               aprint_normal("_bmc_io_wait: wakeup success\n");
                sc->sc_wakeup = 0;
                wakeup(sc);
                return;
        }
 
        if (++sc->sc_retries > sc->sc_max_retries) {
+               aprint_normal("_bmc_io_wait: wakeup failure\n");
                sc->sc_wakeup = 0;
                wakeup(sc);
                return;
        }
 
+       aprint_normal("_bmc_io_wait: callout\n");
        callout_schedule(&sc->sc_callout, 1);
 }
 
@@ -1756,6 +1760,7 @@
        sc->sc_max_retries = hz / 2; /* 0.5 seconds max */
        callout_init(&sc->sc_callout, 0);
        callout_setfunc(&sc->sc_callout, _bmc_io_wait, sc);
+       aprint_normal("Callout initialized at %p\n", &sc->sc_callout);
 
        /* Map registers */
        ipmi_map_regs(sc, ia);

And I get this output:

attimer0: attached to pcppi0
_bmc_io_wait: sc=0xffffffff807dea30, a=0xffffffff807de900
_bmc_io_wait: callout
uvm_fault(0xffffffff806e7ae0, 0x0, 1) -> e
fatal page fault in supervisor mode

It looks to me like _bmc_io_wait() is called before "sc->sc_callout"
has been initialized.

        Kind regards

-- 
Matthias Scheler                                  http://zhadum.org.uk/