[9fans] CDrom question

[9fans] CDrom question

[Jean Mehat]

When I boot a NEC Versa Note under Plan 9, the CDrom reader is detected as:
dev B0 config 85C0 capabilities 2F00 mwdma 0407 dma 00000004 rwm 0

I start 9660srv and try to mount the cdrom:
	term% 9660srv -v
	9660srv 81: serving /srv/9660
	term% mount /srv/9660 /n/cdrom /dev/sdC1/data
	session...OK
	attach(fid=159,uname="jm",aname="/dev/sdC1/data",auth="")...alloc "/dev/sdC1/data", dev=3...xread 3,16...decref=0, "/dev/sdC1/data", dev=3...purgebuf...I/O read error
	mount: mount /n/cdrom: I/O read error

I can copy the cdrom, but when I try to mount the file, 9660srv
reports an unknown format: in a way, the copy failed.
	term% cat /dev/sdC1/data > foobar
(wait half an hour)
	term% cmp foobar /dev/sdC1/data
	foobar /dev/sdC1/data differ: char 32769

Copying only the beginning of the cdrom, dd reports partially transfered blocks
	term% dd < /dev/sdC1/data > foobar -count 1024
	878+146 records in
	878+146 records out
(in a consistent way)
	term% cmp <{dd < /dev/sdC1/data -count 1024} foobar
	878+146 records in
	878+146 records out
	term%

Enabling or disabling dma via /dev/sdC1/ctl doesn't change anything.

As far as I know, the reader works ok under FreeBSD, where it is
reported as using PIO4.

Any idea?