> How do you think about some MO(Magneto Otpical disk) and PD drives? > > 3.5" 650MB and 1.3GB MO drives should handle 512KB/sector(128MB, > 230MB, 540MB) and 2048KB/sector media(640MB, 1.3GB).
The da driver should handle 2048KB sector sized media right now. If it doesn't for some reason, that is a bug and it should be fixed. > Some PD drives use 2 LUNs. One of them is used for CD drive mode and > another is for PD drive. I don't see any problem with the 2 LUNs. CAM probes all luns and has no restrictions on the device types allowed on those luns. Lun 0 could be handled by the cd driver and lun 1 could be handled by the da driver. > How do you treat write protection? DVD-RAM type II media can be remove > from the cartridge and be read as like as DVD-ROM media by some latest > DVD-ROM drives, for example Panasonic's. But the striped DVD-RAM media > is treat ad read only media by DVD-RAM drive. The cd driver will have to understand that some media can be written to and some cannot. The main reason to use the cd driver for this is that DVD is under the MMC command set that the cd driver is supposed to support. The fact that it doesn't support all of those commands right now is a bug, but that doesn't mean that a new driver type is needed. > In addition, there are many bugy MO drives, ex. cash probelem, and > media, ex. formated media for Windows. They cause to need some extra > error handling. So you need quirk entries. The CD driver already has a quirk facility that could be expanded to handle these bugs. Again, I don't see a compelling reason for writing a new driver over expanding the functionality in the old. > We were very happy to use DVD-RAM/MO/PD drives on FreeBSD-2.2.X, > because pre-CAM SCSI system had the od-driver. We could not use these > devices on FreeBSD-3.X without the new od-driver. How did the da driver fail? -- Justin To Unsubscribe: send mail to majord...@freebsd.org with "unsubscribe freebsd-hackers" in the body of the message
