On Monday 09 October 2006 9:44 am, [EMAIL PROTECTED] wrote: > On 10/9/06, David Brownell <[EMAIL PROTECTED]> wrote: > > On Monday 09 October 2006 9:11 am, [EMAIL PROTECTED] wrote: > > > FWIW, if we really could get 5ms latency with a 4ms buffering > > > requirement, that counts as 'good enough for now' and probably 'good > > > enough for the forseeable future'. > > > > 5 ms latency and 4 ms buffering means 1 ms dropout, yes? > > > > If you want 4 ms buffering, try breaking it into two URBs. > > Will we actually acheive that 1ms?
Come on, do the very simple math there. IRQ latency == 5 msec, but only 4 msec queued. 5 - 4 = 1. This is not string theory. That obviously means that when you get the max IRQ latency, you are guaranteed to have 1 msec of dropout. And you're likely to start getting it before that max latency too, given other isues. And to be excessively clear here, that 1 ms dropout is a bad thing, and entirely attributable to insufficient, and single, buffering ... that is, to bugs in the driver providing those URBs. ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
