On Mon, Sep 10, 2012 at 06:45:06PM +0530, Pratyush Anand wrote: > Hi Felip, > > Thanks for the clarifications. > > On 9/10/2012 6:29 PM, Felipe Balbi wrote: > >>If my understanding is correct, then I might need to modify dwc3 > >>>driver a bit. only first TRB of the service interval should have > >>>TRBCTL as ISOC_FIRST rest should have TRBCTL as ISOC. > >Why ? IIRC, ISOC_FIRST was a hint to the internal packet scheduler to > >give higher priority to the isochronous packet, right ? Does it make any > >difference for your use case ? > > Databook says: > > > "The first TRB in a Buffer Descriptor must have the TRBCTL field set > to the “Isochronous-First” type while all others have this field set > to “Isochronous”." aaa true :-) I had forgotten about that extra bit of information when using chained TRBs :-s My bad. Please send a patch. > So I thought to modify the code. As of now, ISOC IN does not work > fully with either All Isochronous-First or Isochronous First + > Isochronous implementation (in case of more than one TRB for one > service interval). > May be I am doing some mistake in my code. :( > I am debugging. Will get back with my observations. I think you're perfectly right at the need for ISOCHRONOUS_FIRST flag. My bad. -- balbi
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