Re: set speed for Toshiba CDROM drive ?

Erik Andersen (andersen@inconnect.com)
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
<kraxel@cs.tu-berlin.de> if you want to do this work...

-Erik

--
Erik B. Andersen   Web:    http://www.inconnect.com/~andersen/ 
                   email:  andersee@debian.org
--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
> ftp://ftp.symbios.com/pub/standards/io/x3t10/drafts/mmc/mmc-r10a.pdf
> 
> Jochen
> -- 
>