How to change DVD-ROM speed?

[Jeffrey W. Baker]

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.

Is this ioctl supposed to work on DVD drives? PPC? In MacOS, the DVD
spins quietly when watching movies.

Regards,
Jeffrey

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[Jens Axboe]

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 :-)

--
Jens Axboe

[Jeffrey W. Baker]

On Wed, 27 Jun 2001, Jens Axboe 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?

Best,
Jeffrey

[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

[Jesse Pollard]

>
> 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.

As long as it still works for the combo drives - CD/CD-RW/DVD
Sony VIAO high end laptops, Toshiba has one, maybe others by now.

-------------------------------------------------------------------------
Jesse I Pollard, II
Email: pol...@navo.hpc.mil

Any opinions expressed are solely my own.

[Jeffrey W. Baker]

On Wed, 27 Jun 2001, Jesse Pollard wrote:

> As long as it still works for the combo drives - CD/CD-RW/DVD
> Sony VIAO high end laptops, Toshiba has one, maybe others by now.

OK when I send the patch I'll assume you will test it :)

[Jens Axboe]

On Wed, Jun 27 2001, Jesse Pollard wrote:
> > Excellent. I'd say use the same ioctl if you can, but default to using
> > SET_STREAMING for DVD drives.
>
> As long as it still works for the combo drives - CD/CD-RW/DVD
> Sony VIAO high end laptops, Toshiba has one, maybe others by now.

As long as it has the DVD features, SET_STREAMING must be supported. So
provided that the combos adhere to that part of the spec (ha), it will
work.

--
Jens Axboe

[Jeffrey W. Baker]

On Wed, 27 Jun 2001, Jens Axboe wrote:

> On Wed, Jun 27 2001, Jeffrey W. Baker wrote:
> >
> > 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.

Hrmm, ah, hrmm. Perhaps I need a little help with this one :)

Just for testing, I modified cdrom_select_speed in ide-cd.c to use SET
STREAMING. Working from the Fuji spec, I created a 28-byte buffer, set
the starting lba to 0, the ending lba to 0xffffffff, the read speed to
0x000000ff, and the read time to 0x000000ff, expecting a resulting speed
of 1KB/ms or 1000KB/s[1]. I assign the buffer to pc.buffer and send it on
its way to cdrom_queue_packet_command().

The result is:

CDROM_SELECT_SPEED failed: Input/output error
hdc: status timeout: status 0x80 { Busy }
hdc: DMA disabled
hdc: ATAPI reset complete

Am I barking up the wrong tree? Do I need to use a different function,
or a generic command instead of a packet command?

Regards,
Jeffrey

[1] Interesting that there appears to be enough room in the spec for a
drive transferring 2^32 * 1000 KB/s.