Alan,
This is in response to your post:
http://marc.theaimsgroup.com/?l=linux-scsi&m=112982432526039&w=2
in a thread titled:
  [PATCH] Improve code for detecting errors near the end of a CD

This patch should allow for the flexibility to handle
MMC devices that don't set the valid bit when putting
a lba in the information field.
The patch is against lk 2.6.14-rc5 .

Changelog:
  - make scsi_get_sense_info_fld() yield the sense
    data information field, or 0 if it is not available
  - the return value is the state of the valid bit in
    the sense data

Signed-off-by: Douglas Gilbert <dougg@torque.net>

Doug Gilbert