Re: usbaudio - Stream start causes multiple urbs to be sent rapidly to isosynchronous and sync endpoints

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Phil Quinton wrote:
> "They are submitted to the endpoint's queue.  The actual transmission
> is managed by the controller's hardware and happens later, once per
> microframe."
>
> Okay, but why are the 12 urbs (4 for sync) despatched one every
> microframe ONLY on the initial start of a stream?

In the steady state, a new URB is submitted whenever a URB has been
completed.

Completion happens just after the packet was actually transmitted, so
this behaviour proves that the actual transmission works correctly (once
per microframe).

> I'll just have to get my DIY device to drop or increase the buffer to
> handle 12+ urbs.

Your device never needs to handle more than one packet (per microframe).


Regards,
Clemens

------------------------------------------------------------------------------
_______________________________________________
Alsa-user mailing list
Alsa-user@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/alsa-user



[Index of Archives]     [ALSA Devel]     [Linux Audio Users]     [Fedora Users]     [Fedora Desktop]     [Fedora SELinux]     [Big List of Linux Books]     [Yosemite News]     [Yosemite Photos]     [KDE Users]     [Fedora Tools]

  Powered by Linux