Wander Lairson Costa wrote: > > AFAIK, if the host request less than a packet size for bulk or > interrupt and the data packed is larger than that, the host will > receive an error.
Yes. That's called "babble", and it is a protocol violation. The device can actually trample over the top of the device that was scheduled to immediately follow it. A USB microframe is all scheduled in advance based on the requests the host controller had at the time. The host controller allocates the time very carefully, and assumes everyone behaves. If this babble happens to occur at the end of a microframe, so that it steps on the frame boundary, it can actually cause the upstream hub to shut down. I've seen it happen. -- Tim Roberts, t...@probo.com Providenza & Boekelheide, Inc. ------------------------------------------------------------------------------ Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d _______________________________________________ libusbx-devel mailing list libusbx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libusbx-devel
