Subject: Re: More on CD changers
To: Charles M. Hannum <mycroft@MIT.EDU>
From: Kent Vander Velden <graphix@iastate.edu>
List: current-users
Date: 04/06/1996 01:29:49
In message <el2ybo9khnu.fsf@zygorthian-space-raiders.MIT.EDU>, mycroft@mit.edu 
writes:
>
>Laine Stump <laine@morningstar.com> writes:
>
>> Yep. I tested it today and saw about 6.5 - 7 seconds for switching times
>> on the NEC 2x (MBR-7), and between 7.5 and 9 seconds switching for the
>> Pioneer 4x (DRM-624x). 
>> 
>> Since the current NetBSD probe stuff causes each disk to be loaded in
>> turn, [...]
>
>Is this still the case under -current?  I removed the code to probe
>CD-ROM drives at boot time for other reasons, but it should also fix
>this.
>

  No, there does not seem to be a probe of the disks at startup.
Previously it was sort of flaky with the NEC 4Xc at least... the output
was unpredictably displaying the information of only a subset of the
disks.

>> On that subject - at boottime, the probe properly identifies which slots
>> have disks installed on the Pioneer, but fails to do so reliably on the
>> NEC. As far as mounting, I never get an error from the Pioneer, but
>> always from the NEC (the first try after inserting a disk)
>
>Does the kernel output any messages when it fails to mount?  The sense
>data would be very helpful.  (To be more blunt, I can't even begin to
>look at why it does that without the sense data.)  NEC CD-ROM drives
>have been known to violate the SCSI-2 spec in lame and annoying ways,
>but it's possible there's something I can do about it.
>


  Does the following help?

cd0 at scsibus0 targ 3 lun 0: <NRC, MBR-7.4, 101> SCSI2 5/cdrom removable
cd1 at scsibus0 targ 3 lun 1: <NRC, MBR-7.4, 101> SCSI2 5/cdrom removable
cd2 at scsibus0 targ 3 lun 2: <NRC, MBR-7.4, 101> SCSI2 5/cdrom removable
cd3 at scsibus0 targ 3 lun 3: <NRC, MBR-7.4, 101> SCSI2 5/cdrom removable
cd4 at scsibus0 targ 3 lun 4: <NRC, MBR-7.4, 101> SCSI2 5/cdrom removable
cd5 at scsibus0 targ 3 lun 5: <NRC, MBR-7.4, 101> SCSI2 5/cdrom removable
cd6 at scsibus0 targ 3 lun 6: <NRC, MBR-7.4, 101> SCSI2 5/cdrom removable

  The only message that I see that the kernel has generated while trying
to get an error was:

Apr  6 01:22:04 pseudo /netbsd: cd0(aha0:3:0): not ready, data = 00 00
00 00 00 00 00 00 00 00

  Now for some reason I am unable to mount the cd that I mounted.  Seems
that if a disk is inserted while another disk is mounted the original
disk can not be unmounted (even with the -f switch).  Oh well.

---
Kent Vander Velden
graphix@iastate.edu