an array of fixed-sized channel_softc elements. This way IDE controllers
which more than 1 channel (pciide) can extend the channel data easily
for private needs.
To avoid the double dereference at runtime, change the argument of
wdcstart() to the channel data pointer instead of the array index.
Return XS_SENSE when the full sense info has been retrieved, or
XS_SHORTSENSE if only the sense key was available (from the error register)
Make atapi_interpret_sense() deal with this, and call scsipi_interpret_sense()
for XS_SENSE. (XXX sd_interpret_sense() and the ioctl code needs to be made
aware of XS_SHORTSENSE too ! sense hanlding for these is now less broken for
devices that support 'REQUEST SENSE')
All the ATAPI devices I have access to seems to honnor the SENSE_REQUEST
command, but I suspect some ATAPI devices will not (althouh it's mandatory).
The code should be able to deal with this, but is untested ...
in the printing of DMA mode (piix3/4 only)
others: set the debug_mask to 0, so that debug messages are turned off by
default but can be easily turned on.
Reset drive_flags to 0 for unconfigured devices, so that they are ignored
later. For configured devices, reset state to 0 after probe/attach.