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Date: Thu, 31 Jul 1997 03:56:39 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199707301756.DAA26679@godzilla.zeta.org.au>
To: cgull@smoke.marlboro.vt.us, freebsd-current@FreeBSD.ORG
Subject: problems with IDE DMA
Sender: owner-freebsd-current@FreeBSD.ORG
X-Loop: FreeBSD.org
Precedence: bulk

After successfully testing IDE DMA for a little while (reading rwd0,
fsck -n and bonnie -s 64 worked fine) I got the following messages
after the write stages for bonnie -s 64:

    wd0: interrupt timeout:
    wd0: status 50<rdy,seekdone> error 0
    wd0: interrupt timeout:
    wd0: status 58<rdy,seekdone,drq> error 1<no_dam>
    wd0: interrupt timeout:
    wd0: status 58<rdy,seekdone,drq> error 1<no_dam>
    wd0: interrupt timeout:
    wd0: status 58<rdy,seekdone,drq> error 1<no_dam>
    wd0: Last time I say: interrupt timeout.  Probably a portable PC.:
    wd0: status 58<rdy,seekdone,drq> error 1<no_dam>

The system then drifted South:
- no more interrupt timeouts, but wd seemed to get stuck in single
  sector mode.  ls on the bonnie output file was very slow, and
  systat reported about 20 interrupts/sec, 10 "blks", and often
  "***** msps" (division by 0?).
- long before the 13107 seconds required to read 128MB at 10K/sec,
  the system hung (the keyboard LEDs didn't work).
- the test drive was dead after hard reset.
- the test drive was OK after cycling the power.

Boot-time log messages:

    ...
    ide_pci0: <Intel PIIX Bus-master IDE controller> rev 0x02 on pci0.7.1
    ide_pci: warning, ide0:0 not configured for DMA?
    ide_pci: warning, ide0:1 not configured for DMA?
    ide_pci: warning, ide1:0 not configured for DMA?
    ide_pci: warning, ide1:1 not configured for DMA?
    ...
    wdc0 at 0x1f0-0x1f7 irq 14 flags 0x80ffa0ff on isa
    wdc0: unit 0 (wd0): <QUANTUM FIREBALL_TM2110A>, DMA, 32-bit, multi-block-16
    wd0: 76kB cache 2014MB (4124736 sectors), 4092 cyls, 16 heads, 63 S/T, 512 B/S

I tested before I noticed the error messages.  DMA did work.

Bruce