Re: How to change DVD-ROM speed?

[Jens Axboe]

On Wed, Jun 27 2001, Jeffrey W. Baker wrote:
> > On Wed, Jun 27 2001, Jeffrey W. Baker wrote:
> > > I am trying to change the spin rate of my IDE DVD-ROM drive.  My system is
> > > an Apple PowerBook G4, and I am using kernel 2.4.  I want the drive to
> > > spin at 1X when I watch movies.  Currently, it spins at its highest speed,
> > > which is very loud and a large power load.
> > >
> > > /proc/sys/dev/cdrom/info indicates that the speed of the drive can be
> > > changed.  I use hdparm -E 1 /dev/dvd to attempt to set the speed, and it
> > > reports success.  However, the drive continues to spin at its highest
> > > speed.
> >
> > Linux still uses the old-style SET_SPEED command, which is probably not
> > supported correctly by your newer drive. Just checking, I see latest Mt
> > Fuji only lists it for CD-RW. For DVD, we're supposed to do
> > SET_STREAMING to specify such requirements.
> >
> > Feel free to implement it :-)
> 
> I will be happy to :)  Should I hang conditional code off the existing
> ioctl (CDROM_SELECT_SPEED, ide_cdrom_select_speed) or use a new one?

Excellent. I'd say use the same ioctl if you can, but default to using
SET_STREAMING for DVD drives.

-- 
Jens Axboe