Re: [linux-audio-dev] 1.5 ms latency possible?

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Subject: Re: [linux-audio-dev] 1.5 ms latency possible?
From: David Olofson (david_AT_olofson.net)
Date: Wed Jan 01 2003 - 00:34:53 EET

On Tuesday 31 December 2002 23.24, Anders Torger wrote:
[...]
> I've thought about RTLinux actually, but it is simply too much
> work, porting drivers to start with...

You can probably get away with using normal drivers (OSS or ALSA) in
mmap() mode, and hooking the interrupt with an RTLinux or RTAI ISR.
Start up the I/O from user space as usual, and then divide the IRQ
period into the number of fragments you need, using an RTL or RTAI
periodic thread. Just keep in mind that PCI cards generally have a 64
byte PCI burst size limit, so going below that won't work.

//David Olofson - Programmer, Composer, Open Source Advocate

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