Re: set speed for Toshiba CDROM drive ?

Erik Andersen (
Thu, 7 Aug 1997 13:09:59 -0600 (MDT)

Um. While this approach certainly could work, generally this
is why people write device drivers. You could take a look
at adjusting drivers/scsi/sr.c to support the CDROM_SELECT_SPEED ioctl.
(Actually it may support it these days. I havn't looked since 2.1.10)
To add this you would need to change the cdrom_device_ops struct named
sr_dops so that instead of a NULL pointer for the line that has the
/* select speed */ comment it actually points to a function (give it
a creative name like sr_select_speed). Then all you need to do is
write a sr_select_speed function that slams down the appropriate
SCSI commands. May I recommend you get in touch with Gerd Knorr
<> if you want to do this work...


Erik B. Andersen   Web: 
--This message was written using 73% post-consumer electrons--

On Thu, 7 Aug 1997, Jochen Karrer wrote:

> Hi, > > does anyone know how to set the media speed (1x, 2x, 6,7x) for > > TOSHIBA XM-3701 cdrom drive ? I'd like to have some ioctl() or similar > > where I can redure the speed to 2x or 1x when I get read/positioning errors > > for flaky CDR disks. > > There is a SCSI-Command SET-CD-SPEED (0xbb). I never tried, because > I have no SCSI CDrom. > > > > did anyone already implement this ? > Take any tool which accesses the generic SCSI-Interface > ( ziptool.c, hpscanpbm.c, coolscan.c ) and add a > SCSI-Command 0xbb. > > > or where can I get the information how to change the speed > > (which SCSI mode page and bytes/bits) ? > > page 69 > > > Jochen > -- >