On Fri, 16 Nov 2001, Ian Pratt wrote: > It definitely appears to be some sort of timeout issue. I've > appended an irdadump output, captured while downloading a file > from the network i.e. most dataflow from the phone to the laptop. > As you can see, there are fairly regular ~500ms breaks in the > transmission.
The 500ms thing is the normal media access duration granted to the phone. The point is after some 3x20=60ms or so the phone has nothing to transmit anymore as indicated by the pf=1. If there is something to send to the phone your box goes on transmitting immidiately (i:cmd) - fine. If there is nothing to send however, it does the normal wait until the end of the turn period without reclaiming the remaining time - correct protocol but not so good for latency. Seems I forgot to ask the obvious: have you compiled the IrDA stack with CONFIG_IRDA_FAST_RR enabled? Doesn't look so. With this option the stack would send the rr:cmd (which grants another media access time) to the phone and you should be happy. It's an IrDA option to be enabled during the kernel configuration. > I don't really know how to read irdadump output, but does "rr" > indicate a retransmit? If so, of what? The last packet before > the delayed "rr" packet always seems to come from the phone, not > from the laptop as you'd expect. Nope, rr.cmd means the primary irda stack has nothing to send and yields the media to the secondary (phone). There's nothing wrong with this, except it shouldn't wait until the end of the 500ms turn time if the phone has pf=1 set - that's exactly what CONFIG_IRDA_FAST_RR will do. > I've currently got Martin's patch cooking and will report back. AFAICS there is no indication of any packet loss in your dump. If this was obtained without my patch it would demonstrate my concern about mtt=0 was not the cause for your problem. Btw., I'm wondering whether there is any reason to have FAST_RR not enabled by default - power consumption? Martin PS: Ian, I've just realized all the CC's to you got just bounced - sorry. Seems your ISP doesn't allow you to receive mail from dialup-mailer ;-) I hope reading on linux-irda is ok for you. _______________________________________________ Linux-IrDA mailing list - [EMAIL PROTECTED] http://www.pasta.cs.UiT.No/mailman/listinfo/linux-irda
