Re: anyone know what's going on in dw780_errchk

[Brad Parker <brad%heeltoe.com@localhost>]

Anders Magnusson wrote:
...
>> is that a hardware error register?
>> 
>Yep.  And since the unibus adapter bits are clear-on-one the bits are just
>read and written back to clear them.

yes, it appears to be the unibus status register, called "uba_sr" elsewhere

usually, while probing, I either see zero (if the device exists) or 
1 (UBASR_UBSSYNTO - UNIBUS slave sync timeout).

But in this odd case, I see it probe for the UDA50, which works, then it
calls the driver probe, which works, but after the driver probe it checks
uba_sr again and sees 0x10 (UBASR_IVMR - invalid map register)

which causes it to ignore the device.

I think I've determined that it's something to do with the state of the
UDA50 after 'boot' gets done.

if I just nfs boot via de, the uda probe works

if I do a failed ra boot first (bad kernel name) and then nfs boot, the
 uda probe fails.

odd.

-brad