Re: New CD/DVD reports 'Can Play Audio NO'

[Tejun Heo]

(cc'ing Bartlomiej, hi!)

Boris Petkov wrote:
> On Tue, Oct 14, 2008 at 8:53 AM, Tejun Heo <tj@xxxxxxxxxx> wrote:
>> Nick Warne wrote:
>>> /messages
>>> Oct  5 11:54:13 sauron kernel: ata5: PATA max UDMA/133 cmd 0x1f0 ctl
>>> 0x3f6 bmdma 0xf400 irq 14
>>> Oct  5 11:54:13 sauron kernel: ata6: PATA max
>>> UDMA/133 cmd 0x170 ctl 0x376 bmdma 0xf408 irq 15
>>> Oct  5 11:54:13 sauron kernel: ata5.00: ATAPI: TSSTcorp CDDVDW
>>> SH-S202J, SB00, max UDMA/66
>>> Oct  5 11:54:13 sauron kernel: ata5.01: ATAPI: Optiarc DVD RW AD-7200A,
>>> 1.06, max UDMA/66
>>> Oct  5 11:54:13 sauron kernel: ata5.00: configured for UDMA/66
>>> Oct  5 11:54:13 sauron kernel: ata5.01: configured for
>>> UDMA/66
>>>
>>> /syslog
>>> Oct  5 11:54:13 sauron kernel: sr0: scsi3-mmc drive: 48x/48x writer
>>> dvd-ram cd/rw xa/form2 cdda tray
>>> Oct  5 11:54:13 sauron kernel: sr1:
>>> scsi3-mmc drive: 48x/48x writer dvd-ram cd/rw xa/form2 cdda tray
>>>
>>> /proc/sys/dev/cdrom/info
>>>
>>> drive name:             sr1     sr0
>>> drive speed:            48      48
>>> drive # of slots:       1       1
>>> Can close tray:         1       1
>>> Can open tray:          1       1
>>> Can lock tray:          1       1
>>> Can change speed:       1       1
>>> Can select disk:        0       0
>>> Can read multisession:  1       1
>>> Can read MCN:           1       1
>>> Reports media changed:  1       1
>>> Can play audio:         1       1
>>> Can write CD-R:         1       1
>>> Can write CD-RW:        1       1
>>> Can read DVD:           1       1
>>> Can write DVD-R:        1       1
>>> Can write DVD-RAM:      1       1
>>> Can read MRW:           1       1
>>> Can write MRW:          1       1
>>> Can write RAM:          1       1
>> Thanks.  sr.c just doesn't check whether the drive reports audio play
>> capability or not.  It just sets it while ide-cd actually checks for
>> the capability.  The drive is not reporting it while it can so ide-cd
>> needs blacklist entry for it.  Now that idecd has blacklist entry, all
>> should be fine.  Eh... I'm not sure whether we need to update sr to
>> follow what ide-cd is doing or not.
>>
>> Thanks.
> 
> Actually, as I already pointed out, I'm not at all happy with blacklisting
> stuff. What sounds more sane to me (and this is only me) would be what sr.c
> does: assume that per se the drive can play audio and try to play it. But how
> many drives are there that cannot play audio, aka, would it be a safe assumption
> to say that their number is so diminishingly small that it would be better to
> announce that a drive can play audio by default and fail graciously in the
> _very_ seldom case it actually cannot ...
> 

Hmm... I don't know.  I think the flag indicates whether the drive has
DAC and analog audio output, right?  I have quite some SATA drives which
don't have audio output at all.  I haven't check what they report on the
mode sense page yet.  Eh... well, having the bit set when the drive
doesn't support it doesn't hurt too much (yet).  Bartlomiej, what do you
think?

Thanks.

-- 
tejun
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