regression in ata/atapi wrt dma?

Søren Schmidt sos at
Sun Sep 19 08:18:00 PDT 2004

Michael Nottebrock wrote:
> I just noticed that one of my burners in my homebox isn't set to dma mode 
> anymore on boot (hw.ata.atapi_dma="1" is set in loader.conf.local):
> acd0: DVDR <HL-DT-ST DVDRAM GSA-4081B/A104> at ata1-master UDMA33
> acd1: CDRW <HL-DT-ST RW/DVD GCC-4120B/2.02> at ata1-slave PIO4
> I dual-boot 4-STABLE on this box and there it is:
> acd0: DVD-R <HL-DT-ST DVDRAM GSA-4081B/A104> at ata1-master UDMA33
> acd1: CD-RW <HL-DT-ST RW/DVD GCC-4120B/2.02> at ata1-slave WDMA2

This is the "new worldorder" for ATAPI devices. The default is now to 
enable DMA if the device claims to support at least UDMA33, if not its 
left in PIO mode. This is to avoid all the (old) sucky devices that 
claims DMA but really doesn't work.

If you need any modes beyond this, please use atacontrol.


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