Subject: Re: [linux-audio-dev] es1371 OSS problem
From: Kai Vehmanen (kaiv_AT_wakkanet.fi)
Date: Sun Mar 18 2001 - 15:52:47 EET
On Sat, 17 Mar 2001, Kurt Rosenfeld wrote:
> program http://freshmeat.net/projects/simplemultitrack/ I have discovered
> an unfortunate problem with the Linux Creative/Ensoniq 1371 OSS
> driver. After calling the SNDCTL_DSP_SETTRIGGER ioctl() to stop the ADC
> and DAC, the card should be stopped until the SNDCTL_DSP_SETTRIGGER
> ioctl() is used again to start the ADC and DAC. But a write() call to the
> soundcard file descriptor will start the converters again. The card
There's at least one restriction in the OSS trigger code:
--cut--
Before the application can use the trigger ioctl to start device
operations, the bit to be used should be set to 0. To do this you can
use the following code. It is important to note that this can be done
only immediately after opening the device (before writing to or
reading from it). It is currently NOT possible to stop or restart a
device that has already been active without first reopening the device
file.
--cut--
So, you'll have to go through close-open for triggering to work
again. This is a problem that also affects ecasound.
-- . http://www.eca.cx ... [ audio software for linux ] /\ . . http://www.eca.cx/aivastus ... [ aivastus net radio ] /\ .
This archive was generated by hypermail 2b28 : Sun Mar 18 2001 - 16:10:51 EET