Re: cdrecord-prodvd also fails to write Moviestyle dvd (was: Cannot read anymore dvd after eject and re-load)
Dominique Dumont <domi.dumont@free.fr> wrote:
> scsidev: 'ATAPI:0,0,0'
> devname: 'ATAPI'
> scsibus: 0 target: 0 lun: 0
> Warning: Using ATA Packet interface.
> Warning: The related Linux kernel interface code seems to be
> unmaintained. Warning: There is absolutely NO DMA, operations thus
> are slow. Using libscg version 'schily-0.8'.
> The part about no DMA is weird since hdparm reports that DMA is
> enabled: $ sudo hdparm /dev/hdc
>
> /dev/hdc:
> IO_support = 0 (default 16-bit)
> unmaskirq = 1 (on)
> using_dma = 1 (on)
> keepsettings = 0 (off)
> readonly = 0 (off)
> readahead = 256 (on)
> HDIO_GETGEO failed: Invalid argument
>
> Could someone tell me what's wrong ?
Reading the error/warning output could. I quoted the relevant part
above. You're using the unbelievably old, very, very deprecated "ATAPI"
device interface. This API does not support DMA at all. The fact that
using_dma is on is irrelevant; this API disables DMA no matter what.
Solution: Address the drive as "ATA:0,0,0" instead of "ATAPI:0,0,0".
Note: Noone can guarantee that DMA will work using ATA:. The Linux
kernel drivers seem to be generally crappy in this area. But with this
API, there's at least a theoretical chance for DMA.
@Jörg: Is it actually useful to keep this interface around? Any
real-world reason to use it? I suggest removing it and aliasing ATAPI:
to ATA: in future versions.
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