a number of related problems along the way.
- Automatically detect CDROM drives that can't handle 6 byte mode
sense and mode select, and adjust our command size accordingly.
We have to handle this in the cd(4) driver (where the buffers are
allocated), since the parameter list length is different for the
6 and 10 byte mode sense commands.
- Remove MODE_SENSE and MODE_SELECT translation removed in ATAPICAM
and in the umass(4) driver, since there's no way for that to work
properly.
- Add a quirk entry for CDROM drives that just hang when they get a 6
byte mode sense or mode select. The reason for the quirk must be
documented in a PR, and all quirks must be approved by
ken@FreeBSD.org. This is to make sure that we fully understand why
each quirk is needed. Once the CAM_NEW_TRAN_CODE is finished, we
should be able to remove any such quirks, since we'll know what
protocol the drive speaks (SCSI, ATAPI, etc.) and therefore whether
we should use 6 or 10 byte mode sense/select commands.
- Change the way the da(4) handles the no_6_byte sysctl. There is
now a per-drive sysctl to set the minimum command size for that
particular disk. (Since you could have multiple disks with
multiple requirements in one system.)
- Loader tunable support for all the sysctls in the da(4) and cd(4)
drivers.
- Add a CDIOCCLOSE ioctl for cd(4) (bde pointed this out a long
time ago).
- Add a media validation routine (cdcheckmedia()) to the cd(4)
driver, to fix some problems bde pointed out a long time ago. We
now allow open() to succeed no matter what, but if we don't detect
valid media, the user can only issue CDIOCCLOSE or CDIOCEJECT
ioctls.
- The media validation routine also reads the table of contents off
the drive. We use the table of contents to implement the
CDIOCPLAYTRACKS ioctl using the PLAY AUDIO MSF command. The
PLAY AUDIO TRACK INDEX command that we previously used was
deprecated after SCSI-2. It works in every SCSI CDROM I've tried,
but doesn't seem to work on ATAPI CDROM drives. We still use the
play audio track index command if we don't have a valid TOC, but
I suppose it'll fail anyway in that case.
- Add _len() versions of scsi_mode_sense() and scsi_mode_select() so
that we can specify the minimum command length.
- Fix a couple of formatting problems in the sense printing code.
MFC after: 4 weeks
56eac725a3