Sound interference when using speakup.

[Kerry Hoath]

Although speakup is involved in the broken audio problems;
you can make a huge difference by optimizing your
ide setup.
By using hdparm you can unmask interrupts set multi sector
transferr and enable dma.
unmasking interrupts lowers latency and allows sound more time to
fill its buffers.
hdparm -u1 /dev/hda
Setting multiple sector mode allows the drive to only drigger an interrupt every
32 sectors or depending on what hte drive supports.
hdparm -i /dev/hda
will identify what the drive can do, look for maxmult. Then 
run the following:
hdparm -m16 /dev/hda
or whatever the maxmult value was.

If Linux supports dma on your controller, you can enable
it like this:
hdparm -d1 /dev/hda
You can do all this in one shot with:
hdparm -d1 -u1 -m16 /dev/hda
Ide transferrs can impact the kernel quite a lot if not managed properly.
Also the apollo hardware design is possitively evil and handshaking is a problem.
I wouldn't be surprised if speakup wasn't eating cpu
managing to deal with the apollo's bizare interfacing.
I have an artic transport and a doubletalk and I don't have audio breakup problems but
other people have described similar stuff with other hardware.

Regards, Kerry.
On Sun, Mar 03, 2002 at 12:04:41AM +0000, Toby Fisher wrote:
> Hi.
> 
> I have here a Duron 600 mhz machine, 768 mb ram, using a Soundblaster Live
> Value sound card, ansd have a eird problem.  When using my Apolo
> synthesiser which is serial-driven in conjunction with the sound card, the
> audio is broken, it is almost as if there is a scheduling problem and
> therefore the audio runs slower, though this only happens while the data
> is actually being sent to the serial port.  I have the sound drivers built
> as modules, but other than that cannot work out why this problem may be
> arising.  As I'm sure you can imagine, it's quite annoying as I'd like to
> be able to listen to music etc hile I'm using the machine.
> 
> Any thoughts?
> 
> As an aside, if I am to donload TRPlayer and therefore Real Player, do I
> still need to install the X libraries and have an X server running for the
> G2 player, as was the case when I last played with it a couple of years
> ago?  I do hope not.
> 
> Cheers.
> 
> 
> -- 
> Toby Fisher	Email: toby at g0ucu.freeserve.co.uk
> Tel.: +44(0)1480 417272	Mobile: +44(0)7974 363239
> ICQ: #61744808
> 
> 
> 
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-- 
Kerry Hoath:  kerry at gotss.net kerry at gotss.eu.org or  kerry at gotss.spice.net.au