[alsa-devel] Audiophile Delta 24/96 Midi Out continuously sends zeroes (alsa 1.0.14)

Clemens Ladisch cladisch at fastmail.net
Mon Sep 3 17:29:45 CEST 2007

Romain Bossart wrote:
> Selon Clemens Ladisch <cladisch at fastmail.net>:
> > That is, the zeroes are _not_ sent when you're not using jack?  When
> > nothing is connected, or when you use aplaymidi or amidi to send
> > something, everything is OK?
> Here is a summary of the various tests I did. I have just one card: Audiophile
> Delta 24/96. My kernel is now RT patched & alsa 1.0.14,
> Audio works perfectly. I don't think jack is the problem.
> Config #2 = Delta Midi Out -> (Midi In) Instrument (Midi Out/Thru) -> Delta Midi
> In and 'amidi -p hw:0,0 -d'. Jack being started or not.
> Symptoms: tons of zeroes are shown by amidi as soon as I launch it. The stream
> is so intense I can actually hear it in my speakers/monitors (need to switch to
> better MIDI cables, I know!). amidi and /proc/asound/card0/midi0 give the same number
> of transmitted bytes.

With "transmitted", you meant "received"?
When Jack is not running, there is no software to send anything.  If the number
of _transmitted_ bytes changes anyway, this would be a bug in ALSA.

> Config #2b = Delta Midi Out -> Delta Midi In
> and 'amidi -p hw:0,0 -d', Jack being started or not.
> Symptoms: identical to config#2. Moreover, if meanwhile I send some Midi commands
> with amidi ('amidi -p hw:0,0 -S C01C'), I don't find this data in my dump.

Apparently, the output port is broken.  While it is theoretically
possible that the driver doesn't initialize the card correctly, I cannot
imagine a bug that would cause the port to presume that there is data to

Could you test if the port sends data even before the driver (or Linux)
is loaded, or in Windows?


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