Re: writable mmc profiles actually are writable

Jens Axboe
2003-10-07T07:00:50Z

On Mon, Oct 06 2003, Pat LaVarre wrote:
> > patches to make the detection more modern ...
>
> Below appears a copy of an old patch to try op x46 get_configuration any
> time mode page x2a doesn't already say the pdt x05 dvd/cd device is
> writable.

See my comments in another mail.

> > I haven't yet had to deal with dvd+rw or
> > ddcd_rw (is this like mtr?
>
> Sorry I do not know mtr.

mt rainier, different in spirit but allows the same 2kb writes and
handles the rest in hardware.

> > mo and dvd-ram have been supported for a long
> > time and should be set with CDC_DVD_RAM,
>
> Sorry I do not understand. I remember noticing CDC_MO_DRIVE appears
> only drivers/ide/ not in drivers/scsi/. Weakly I conclude mo doesn't
> work the same in atapi and usb-storage.

IIRC, scsi mo drives are handled by sd, not sr.

> > the disk profiles aren't driven by ide-cd or
> > sr.
>
> Sorry I do not understand.
>
> In drivers/scsi/sr.c I find:
> cd->cdi.mask |= CDC_DVD_RAM;
>
> In drivers/ide/ide-cd.c I find:
> devinfo->mask |= CDC_DVD_RAM;
>
> I conclude sr and ide-cd tell cdrom whether the device "profile" is
> writable or not. Is that wrong?

->mask is an inverted capability mask, so if you set CDC_DVD_RAM you
mask that capability.

--
Jens Axboe