linuxaudio.org

On Sun, May 13, 2012 at 4:06 PM, Robin Gareus  wrote:
> Any hints on how to address this issue, then? If I understand correctly,

quoted text
> new USB2-class-compliant devices are not an issue, but on modern

> machines with only EHCI, USB1-class-compliant devices may or may not

> work... right?

The primary problem with EHCI is only bandwidth allocation; it's

inefficient.  I'm unaware of any timing problems.  That's not to say

they don't exist, I just haven't run into them myself.
Poor bandwidth efficiency aside, I usually see ~ the same latency and

timing behavior on UHCi and EHCI with a TT.
> Would forward porting your schedulers be an option? Has anything of this

quoted text
> been merged into recent kernels?

I'm unlikely to do this unless I need it myself, sorry :-(.  Not

enough time, too much to do.  And the kernel devs are absolutely right

that replacing a working but inefficient driver with a brand new one

that is faster but will require long-term testing is not something to

be done lightly.
> Maybe you can do play some tricks on the EHCI controller/scheduler: add

quoted text
> an old USB1.1 hub in between the soundcard and the PC... but that's just

> a shot in the dark.

You'll still be going through the translator in the root hub.
Monty

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