Hi Michael,
Op zo 10 nov. 2019 om 20:26 schreef Michael Schmitz <schmitzmic@xxxxxxxxx>:
case for any of the cards the zorro_esp drives, it might be better to
lower the max length to 61440 (64k-4k) so the residual is a page.
For the benefit of keeping the code simple, and avoid retesting the
fastlane board, that might indeed be the better solution.
But it's slower... :-P
I wonder what max. transfer size had been used so far, in the majority
of cases. I hadn't observed this bug in my tests of the ESP driver on
elgar. So it might not matter so much in practice.
Does Elgar indeed have a Blizzard 2060 as
https://wiki.debian.org/M68k/Autobuilder says?
If it does, it does surprise me that it works, since the DMA engine
appears to be very much like the one
of the Blizzard 1230 (including the >> 1 of the address).
Even when just loading bash on my system, there were many
65535-and-then-1 byte transfers.
It may of course depend on how fragmented your disk is.
Also, I may be adding another board-specific version for the Blizzard
12x0 IV to enable 24-bit transfers, like the am53c974 driver does, in
a later patch.
If we can differentiate between the Mark IV board and the Mark II board
in a reliable way, fine. I can't remember whether I've had a report on
that ever.
They have a different Zorro ID, so that should not be a problem.
By the way, do you remember why you chose to not use the full Zorro
IDs for the various SCSI boards asdefined in zorro_ids.h but only
the manufacturer defines?
Kind regards,
Kars.
