>>Anyone have any ideas on how to track this down?  I'm hoping that the
>>knowledge gained in fixing up -current can be pushed back into 1.6.2.
>
>Out of curiosity, in arch/powerpc/oea/cpu_subr.c, if you set powersave = 0 in
>
>case MPC7447A:
>case MPC7448:
>case MPC7457:
>case MPC7455:
>case MPC7450:
>     /* Enable the 7450 branch caches */
>     hid0 |= HID0_SGE | HID0_BTIC;
>     hid0 |= HID0_LRSTK | HID0_FOLD | HID0_BHT;
>     /* Disable BTIC on 7450 Rev 2.0 or earlier */
>     if (vers == MPC7450 && (pvr & 0xFFFF) <= 0x0200)
>          hid0 &= ~HID0_BTIC;
>     /* Select NAP mode. */
>     hid0 &= ~(HID0_HIGH_BAT_EN | HID0_SLEEP);
>     hid0 |= HID0_NAP | HID0_DPM /* | HID0_XBSEN */;
>     powersave = 1;
>     break;
>
>what happens? Hopefully the 1.6.2 code will be close enough you can locate
>the appropriate place to change 1 => 0. While I was not actively involved
>in rewriting the interrupt code, I learned a great deal about it and found
>that not enabling powersave was keeping 604 processors from properly
>catching an interrupt. If you look in the
>arch/powerpc/powerpc/locore_subr.S, you'll see that as long as one thread
>is active, the kernel will not go into powersave mode. Changing the setting
>above will accomplish the same thing, so you could test this without
>running your while(1) loop.
>
>What is the stock CPU?
>
>tim

I'll try the power save thing.

CPUs:

stock:
Jul 15 21:22:20 grace /netbsd: cpu0 at mainbus0: 7400 (Revision 2.6), ID 0 (primary)
Jul 15 21:22:20 grace /netbsd: cpu0: HID0 8094c2a4<EMCP,DOZE,DPM,EIEC,ICE,DCE,SPD,SGE,BTIC,BHT>
Jul 15 21:22:20 grace /netbsd: cpu0: 450.00 MHz
Jul 15 21:22:20 grace /netbsd: cpu0: 1MB backside cache


and the upgraded one:
Jul  7 19:35:17 grace /netbsd: cpu0 at mainbus0: 7455 (Revision 2.1), ID 0 (primary)
Jul  7 19:35:17 grace /netbsd: cpu0: HID0 8450c0bc<EMCP,TBEN,NAP,DPM,ICE,DCE,SGE,BTIC,LRSTK,FOLD,BHT>
Jul  7 19:35:17 grace /netbsd: cpu0: 1000.00 MHz
Jul  7 19:35:17 grace /netbsd: cpu0: 256KB L2 cache, 2MB L3 backside cache


(These are old logs, but the machines have not changed)

Thanks,

-dgl-