I installed NetBSD on a new machine I built featuring a
  <TOSHIBA DVD-ROM SD-M1612>

It is basically recognized, but whenever I read large amounts of data
(e.g. pkgssrc, syssrc) the drive hangs periodically and produces the
following read error:


 pciide0:1:0: lost interrupt
        type: atapi tc_bcount: 2048 tc_skip: 0
 pciide0:1:0: bus-master DMA error: missing interrupt, status=0x21
 cd0: transfer error, downgrading to Ultra-DMA mode 1
 cd0(pciide0:1:0): using PIO mode 4, Ultra-DMA mode 1 (using DMA data transfers)
 wdc_atapi_intr: bad data phase DATAOUT
 cd0: transfer error, downgrading to DMA mode 2
 cd0(pciide0:1:0): using PIO mode 4, DMA mode 2 (using DMA data transfers)
 pciide0:1:0: lost interrupt
        type: atapi tc_bcount: 2048 tc_skip: 0
 pciide0:1:0: bus-master DMA error: missing interrupt, status=0x21
 cd0: transfer error, downgrading to PIO mode 4
 cd0(pciide0:1:0): using PIO mode 4
 wdc_atapi_intr: bad data phase DATAOUT


This happens with the generic kernel as well with the system specific
that I have compiled myself. Reading about Ultra-DMA problems I disabled
DMA in BIOS for the DVD (Secnd Master), but it still gets detected as
Ultra-DMA 2 capable at bootup.

Might this be a hardware incompatibility? I thought DVDs were generic ATAPI
devices and thus supported.

Thanks a lot for any hints! =)
-- 
DANIEL¯¯Atmos.Phys.Group/Univ.ofBerne/CH mailto:gerber@mw.iap.unibe.ch
GERBER  Encrypted Mail Welcome. Get PGP-Key at http://silvara.unibe.ch
|_"Today is the tomorrow you worried about yesterday."_____________McQ