svn commit: r228808 - head/sys/cam/scsi

[Alexander Motin]

On 22.12.2011 20:24, Andriy Gapon wrote:
> on 22/12/2011 18:40 Alexander Motin said the following:
>> Author: mav
>> Date: Thu Dec 22 16:40:35 2011
>> New Revision: 228808
>> URL: http://svn.freebsd.org/changeset/base/228808
>>
>> Log:
>>    Make cd driver to handle Audio CDs, reporting their 2352 bytes sectors to
>>    GEOM and using READ CD command for reading data, same as acd driver does.
>>    Audio CDs identified by checking respective bit of the control field of
>>    the first track in TOC.
>>
>>    This fixes bunch of error messages during boot (GEOM taste) with Audio CD
>>    inserted and allows to grab Audio CD image using just dd.
>
> Thank you!
> What about CDs with mixed audio and data tracks?
> I don't ask for any support, just curious if our users could run into any
> troubles with those.

If data track is the first (I don't know whether it is mandatory, but 
wiki tells it is usual), the whole disk will be handled as data by the 
driver and work as before (only data part will be readable). If it can 
be not the first, then I am not sure how acd driver works with it, but 
we can just make check a bit more strict, switching to data if found it 
anywhere on disk. Any way I don't think we will see many Mixed Mode CDs 
in the future, while Audio CDs are still on market.

If you worry about audio extraction of Mixed Mode CDs, then quick look 
on mplayer and it's underlying cdparanoia and libcdio shows that they 
are extracting audio data talking directly to the drive using SCSI 
commands, so cd driver is irrelevant for them. So this change is mostly 
about staying consistent when possible with a small blood.

-- 
Alexander Motin