Re: I did a test on a DEC AlphaStation 600 and the SCSI driver seems borked

On 2/16/26 9:37 PM, Jason Thorpe wrote:
> 
> 
>> On Feb 16, 2026, at 9:17 PM, Jason Thorpe <[email protected]> wrote:
>>
>> Anywho, I think the easiest short-term workaround is to ensure the “isp” driver doesn’t use the 64-bit version of the command, which should be fine since:
>>
>>         isp->isp_dmatag = pa->pa_dmat;
> 

I was just reading your other email and it seems that you have detailed 
insights into this problem. I still wonder about the 32-bit DMA clamp
wherein we have little interest in the 64-bit DMA possibility.

As you say .. the hardware will likely not need 64-bit DMA.


> Unless I’m completely wrong, this diff should avoid the problem:
> 
>      https://www.netbsd.org/~thorpej/isp-dma64-avoidance-diff.txt
> 

I can not build on my DEC Alpha for obvious reasons.
However it may be possible on a QEMU instance.


> Unfortunately, I’m not able to build you an install media image for another week or so.  If someone else wants to volunteer to build a NetBSD 11 branch installer image with this patch applied, that would be swell.
> 

I would need to know the intricate details of how one creates an ISO9660
bootable image. I suspect it is the usual mkisofs type deal but with
some bootable magic. Therein lay the seeds of wasted CD-R.

No rush. I have at least a week before the new memory DIMMs arrive.

-- 
--
Dennis Clarke
RISC-V/SPARC/PPC/ARM/CISC
UNIX and Linux spoken