Re: [LAU] USB card oddness

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To: Bob van der Poel <bob@...>
Cc: Linux Audio User <linux-audio-user@...>
Date: Wednesday, December 11, 2013 - 1:35 am

It doesn't have to be; what matters is that's it being scheduled into
a space that fragments the bandwidth the audio device needs.

Even if the audio device only needs 3% of the bandwidth and the mouse
.0001%, the mouse drops that USB frame into low-speed compat mode and
blocks all higher speed devices from using any bandwidth during that
timing period. If the audio device requires a tiny, uninterrupted
piece of scheduling every period, it's just lost any chance of
successful scheduling.

On top of this, the Linux host schedulers are not particularly
effective about avoiding these conflicts.

[sorry for some ambiguity above; I don't remember if 1.0/1.1 drops a
full frame to low speed or just the microframe].

Monty

On Tue, Dec 10, 2013 at 8:28 PM, Bob van der Poel wrote:

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Messages in current thread:
[LAU] USB card oddness, Bob van der Poel, (Tue Dec 10, 10:12 pm)
Re: [LAU] USB card oddness, Gabriel M. Beddingfield, (Wed Dec 11, 1:04 am)
Re: [LAU] USB card oddness, Bob van der Poel, (Wed Dec 11, 1:29 am)
Re: [LAU] USB card oddness, Monty Montgomery, (Wed Dec 11, 1:35 am)