USB audio playback async feedback problem

[FWD]

Hi USB experts

I met a problem when try to use audio feedback.

config:
High-speed, ISO data ep: binterval is 4,ep address=0x01, bRefresh=0,bSyncAddress=0x81
ISO Feedback ep: binterval is 4, address is 0x81,bRefresh=7,bSyncAddress=0

the enumeration is successful, but when open audio playback, the player cannot playback.
From the trace, when open the player, host set alternate setting 1, then set alternate setting 0(stop playing)
It is very weired.


This  issue is resolved.

[Jan Axelson]

A hardware protocol analyzer might provide a clue such as a failed attempt at communicating.

Here is another discussion about audio feedback:

http://www.lvr.com/forum/index.php?topic=1116.msg4841

[FWD]

A hardware protocol analyzer might provide a clue such as a failed attempt at communicating.

Here is another discussion about audio feedback:

http://www.lvr.com/forum/index.php?topic=1116.msg4841

Yes, Host just send 2 control transfer,  set interface 1 and set interface 0, no other traffic is
observed.
I tried the firmware on Win7&Win8, both have this scenario.

If  I set the data iso ep attribute to adaptive or sync type, the audio player can play music.

I am wondering if the OS support feedback.

Thanks
FWD

[FWD]

A hardware protocol analyzer might provide a clue such as a failed attempt at communicating.

Here is another discussion about audio feedback:

http://www.janaxelson.com/forum/index.php?topic=1116.msg4841

I have reviewed that post, mainly discussed the feedback refresh time.
Now my issue is feedback cannot work at all.

thanks
FWD

[G40]

Have you got access to a mac to check your firmware is doing the right thing?

https://developer.apple.com/library/mac/technotes/tn2274/_index.html#//apple_ref/doc/uid/DTS40010116-CH1-TNTAG7_2

I am not sure aysnc feedback mode is supported on Windows. Have you tried checking the ETW logs or getting the Microsoft USB tools?

[FWD]

thanks, the issue has been resolved.
there's an error in the descriptor.