[alsa-devel] Tascam US122 on Arm

ST st at iss.tu-darmstadt.de
Thu Oct 4 10:43:27 CEST 2007


Hi Micheal
> -1 in a 16-bit integer (which would be 65535 if unsigned), and the
> driver is putting it in a 32-bit integer without sign extension and
> incrementing it as though it is the number of the usb frame. 
Thats an interesting idea. I think i will take a look at the code if this is 
the case.
> Look 
> through the driver code to see where that value is assigned to a
> variable, and find out what function is doing it.  Basically, since
> it's happening right after the limits of a 16-bit integer, I'd say
> it's either an overflow error, or an error code is being returned in
> the wrong kind of variable (signed vs. unsigned).  In my case, what
> solved my USB error messages was disabling PowerNow CPU frequency
> scaling.
Intresting. I got a different mail 
http://www.nslu2-linux.org/wiki/Peripherals/AudioAdapter
Since i have an 1.0 Soundcard and EHCI ports this is probably one cause of the 
problem.

Currently i have taken out the call usX2Y_clients_stop(usX2Y); in the function
usX2Y_error_sequence and added an subs->completed_urb = urb; to the 
corresponding else statement. Since them i didn't had any errors reported, 
but i suspect i did an error somewhere, since the error occured on every 
playback and now i don't get any usb glitches reported. I will test it a 
little bit more and get back with some results.

Best regards
ST


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