Re: I/O bus reset to fix CMD MSCP controllers (and probably others)

Could you see if there are any writes to the IP register? That would be 
the software reset of just that controller.

   Johnny

On 2025-03-31 15:43, Mouse wrote:
>> And now we're having these issues on NetBSD, too. I really wonder
>> whether NetBSD might have done a I/O bus reset in the past that went
>> missing during some refactoring or rototilling.
> 
> Data point: when I boot 1.4T under my emulator, I see only three I/O
> resets.  One is the emulator resetting itself during startup.  The
> other two are due to writes to IPR 55, which happen:
> 
> - Early in the ROM code (before terminal type detection starts).
> - After the "b dua0" command but before the "2..1..0.." prints.
> 
> I do not see any others.  In particular, I do not see any at any point
> between the ">> NetBSD/vax boot ... <<" line and the single-user shell
> prompt.
> 
> Of course, I also do not know whether 1.4T works with the hardware in
> question.  But it does indicate that, at one point some time ago,
> NetBSD didn't do any explicit I/O resets in that code path.
> 
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Johnny Billquist                  || "I'm on a bus
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