[alsa-devel] USB asynchronous mode feedback format

Julian Scheel julian at jusst.de
Thu Oct 14 07:57:58 CEST 2010

Hi Alex,

"Alex" <lee188 at singnet.com.sg> schrieb:

>The current alsa rate feedback rate feedback format is
>12.13 in 4 bytes.  Clemens has a patch to make the rate
>feedback format automatic such that it will work with
>10.14 16.16 or any other formats.  We are still testing the
>patch put .  Currently with 12.13 format rate feedback
>works well.

How does it come that alsa uses 12.13? I don't see that mentioned in the specs?
Is it right or left aligned in the 4 bytes?

>For example, AT91SAM7 has a limitation of EP siE of 64
>bytes for EP 3 used for ISO transfers.  There may also be
>a limitation in that the Same EP number cannot be used
>for both IN and OUT.

Hm, I'm not sure about this. You think I should move the feedback pipe into it's own EP?
I will recheck the At91SAM7 specs later, to see if I can find a note on such a limitation.


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