[PATCH] Fix IDE bus reset and DMA disable when reading blank DVD-R

[PATCH] Fix IDE bus reset and DMA disable when reading blank DVD-R

From Jon Burgess:

  There is a problems with blank DVD media using the ide-cd driver.

  When we attempt to read the blank disk, the drive responds to the read
  request by returning a "blank media" error.  The kernel doesn't have
  any special case handling for this sense value and retries the request
  a couple of times, then gives up and does a bus reset and disables DMA
  to the device.

  Which obviously doesn't help the situation.

  The sense key value of 8 isn't listed in ide-cd.h, but it is listed in
  scsi.h as a "BLANK_CHECK" error.

  This trivial patch treats this error condition as a reason to abort
  the request.  This behaviour is the same as what we do with a blank CD-R.

  It looks like the same fix might be desired for 2.4 as well, although
  is perhaps not so important since scsi-ide is normally used instead.