[issue1158] Problems with a SATA DVD burner

[Hasso Tepper]

Follow up ...

* My SATA CD/DVD writers fine now for reading data at least. Ie. I can 
  install DragonFly with all these.

* The main part of fix I committed today was to disable DMA in atapicam 
  for all commands except READ_* and WRITE_*. It isn't correct fix of 
  course, but rather workaround. My (rather wild) guess is that alignment
  is the real problem. Little googling gives some hints that for SATA 
  ATAPI DMA alignment padding DMA transfers to the 4 bytes boundary is 
  required, but the current ATA code only quarantees 2 bytes boundary.
  I haven't investigated it too closely though and don't have time for 
  that now.

  [See http://osdir.com/ml/ide/2005-07/msg00261.html for example.]

* Cdrecord/wodim hanging seems to be a different issue. Attempting to 
  write second DVD (yes, the first one works) gives me this:

  Nov 17 13:33:09 hasso sudo:    hasso : TTY=ttyp6 ; PWD=/home/hasso ; 
    USER=root ; COMMAND=/usr/pkg/bin/cdrecord -v test.img
  Nov 17 13:33:10 hasso kernel: acd0: FAILURE - READ_BUFFER ILLEGAL 
    REQUEST asc=0x24 ascq=0x00
  Nov 17 13:33:10 hasso kernel: acd0: FAILURE - READ_BUFFER ILLEGAL 
    REQUEST asc=0x24 ascq=0x00
  Nov 17 13:33:10 hasso kernel: ata4: FAILURE - non aligned DMA transfer 
    attempted
  Nov 17 13:33:10 hasso kernel: acd0: setting up DMA failed


-- 
Hasso Tepper