Re: VAXstation 3100/30 KA420 SCSI DMA problem on netboot (and fix)

[Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>]

> Hm, interesting bug :-)

Indeed :-)

> So on KA420 the whole 128k DMA memory is enabled by the firmware if 
> booted from a SCSI disk, but not from network?

Yes, I've confirmed reading KA420_STC_MODE shows (by kernel printfs)
0x01 on DKA0 (sd0) boot but 0x00 on ESA0 (le0) boot.

> I do not have any docs for either of the 3100's, but if it works for you 
> on real hardware it sounds correct.  So go ahead!
> 
> About the /m76, no idea.  We leave it for now until someone with that 
> hardware can test if it is needed.

Ok, I'll commit the fix and send a pullup request for netbsd-10 and -9.

> Thanks for searching for this!

No problem, thanks for your quick review.
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Izumi Tsutsui