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
