[nSLUG] Sound problem (isn't there always?)

Aaron Spanik a.spanik at ns.sympatico.ca
Sat Oct 11 11:01:38 ADT 2008


On Sat, 11 Oct 2008 05:05:40 -0300
"Daniel Morrison" <draker at gmail.com> wrote:

> 2008/10/11 Mike Spencer <mspencer at tallships.ca>:
> 
> > Just installed Slackware 12.1.  All is well. Er, well, most is well.
> >
> > Can't play a music CD.
> 
> > This is a Dell Dimension 3000 w/ Intel P4 CPU and (according to lspci)
> > Intel 82801EB/ER (ICH5/ICH5R) Audio Controller.
> 
> > There are two drives: One CD and one CD/RW.  The above problem occurs
> > whether I point /dev/cdrom to /dev/hdd or /dev/hdc (with a CD in the
> > appropriate drive, of course.)
> 
> Have you ever played a music CD on this hardware before (another OS)?
> 
> If not, I'll bet neither CDROM is patched into your sound card.
>
> Remember that playing audio CDs is an analog operation.  The IDE
> interface tells the CD drive to 'play', and analog audio comes out of
> the dedicated left/right/ground audio connector on the drive itself,
> and must be attached to your sound card's (motherboard's) CD or AUX
> inputs using one of those CD analog audio cables that come in about
> three hundred different flavoured ends.
>
> In fact, this might work even if Linux doesn't support your audio
> chipset at all.  So long as the default mixer/amp level is audible,
> (analog) sound will come out of your headphone jack.  Also, you don't
> need OS support for your CDROM drive, if your drive has a 'play'
> button.  If your CDROM drive has both a 'play' button and a headphone
> jack, you don't even need a computer!  Just power up the drive!

While many older CD-ROMs would output analog via a patch cable to the
sound card, most of the CD/DVD drives you buy today no longer even have
that connector on the back (and many soundcards and motherboards no
longer have the connector either). Playing audio CDs on a modern linux
usually involves transferring the data off the disc and using the
soundcard to do the DAC.

You can try running cdparanoia with a disc in one of the drives:

	# cdparanoia -vsQ

This will, at the very least, tell you what device nodes the system is
using for your CD drive.  I suspect it's using /dev/sr?, instead of
/dev/hd?. Fr'instance, I've got a Pioneer DVD reader/writer in a box
with an ICH7 chipset; it's connected via an IDE cable to an IDE port on
the motherboard, but comes up as /dev/sr0:

 skwidly:~ # hwinfo --cd
18: SCSI 100.0: 10602 CD-ROM (DVD)                              
  [Created at block.238]
  UDI: /org/freedesktop/Hal/devices/storage_model_DVD_RW__DVR_110D
  Unique ID: KD9E.cNDVdXs5_+5
  Parent ID: w7Y8.AxSVys2yNA7
  SysFS ID: /class/block/sr0
  SysFS BusID: 1:0:0:0
  SysFS Device
Link: /devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0
Hardware Class: cdrom Model: "PIONEER DVD-RW  DVR-110D"
  Vendor: "PIONEER"
  Device: "DVD-RW  DVR-110D"
  Revision: "1.22"
  Driver: "ata_piix", "sr"
  Driver Modules: "ata_piix"
  Device File: /dev/sr0 (/dev/sg1)
  Device
Files: /dev/sr0, /dev/scd0, /dev/disk/by-path/pci-0000:00:1f.2-scsi-1:0:0:0, /dev/cdrom, /dev/cdrw, /dev/dvd, /dev/dvdrw
Device Number: block 11:0 (char 21:1) Features: CD-R, CD-RW, DVD,
DVD-R, DVD-RW, DVD+R, DVD+RW, DVD+DL Config Status: cfg=no, avail=yes,
need=no, active=unknown Attached to: #5 (IDE interface)
  Drive Speed: 40

If the ICH5 has SATA capability, this is most likely your issue, as I
believe this might have to do with how the ata_piix driver does IDE.

Hope this helps,

/a


-- 
Aaron Spanik
a.spanik at ns.sympatico.ca



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