CDRW Stopped Working Moving to 6.x

Lowell Gilbert freebsd-questions-local at
Wed Sep 19 12:24:18 PDT 2007

"Crist J. Clark" <cristclark at> writes:

> On Fri, Sep 14, 2007 at 07:35:24AM -0400, Lowell Gilbert wrote:
>> "Crist J. Clark" <cristclark at> writes:
>> > Looking at the dmesg(1) from the last boot,
>> >
>> >   # fgrep cd0 /var/run/dmesg.boot
>> >   acd0: CDROM <CRD-8400B/1.06> at ata1-master UDMA33
>> >
>> > Makes me think the system is not recognizing the device as CDRW,
>> > only CDROM.
>> You're right, and that's the key point to start from.
>> Don't worry about ATAPI/CAM; it won't be used by burncd, and won't
>> work any better than direct ATAPI drivers if the device isn't
>> recognized as a CDRW.
>> The funny thing is (unless I recall incorrectly, which is possible
>> before my first cup of coffee for the day), the ID string is provided
>> by the device itself.  And I just looked it up; CRD-8400B is
>> definitely a CDROM.  So I don't think the OS is confused; if anything,
>> the device itself is what's confused.
>> Just to doublecheck: are you really sure you haven't changed the drive
>> since the last time you burned a CD?
> Nope, haven't changed the drive. Went and had a look at the front and
> it's got "CD/RW" on the "disc" symbol on the front of the tray. But
> going back to some old dmesg(1) from this same box when the buring
> worked back in 4.x,
>   FreeBSD 4.11-STABLE #1: Sun Jun 19 00:18:37 PDT 2005
>       cjc at
>   [snip]
>   acd0: CDROM <CRD-8400B> at ata1-master PIO4
> Hmmmm...

Wow.  Good thinking to check that.

Definitely sounds like you are being bitten by something dodgy in the
device probing which has been there for a long time but was benign in
the past.  You'll need someone who knows the probing code...

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