Re: patch usb-iowarrior.patch added to gregkh-2.6 tree
Guido Körber <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
Am 20.02.2007 um 17:17 schrieb Alan Stern: > On Tue, 20 Feb 2007, Guido Körber wrote: > >> Using maxPacketSize instead of ReportSize is never an option. >> >> maxPacketSize signifies the maximum physical transfer size supported >> by an individual endpoint. This value may be lower, equal, or higher >> than ReportSize. In the last case multiple transfers will be >> conducted to transfer a single report. >> >> If the device defines multiple reports on the same endpoint they >> don't need to have the same size, each single one may have its >> individual size. This is another case where using maxPacketSize will >> fail. >> >> So unless your approach is to accept any report up to maxPacketSize >> it is a bug to use maxPacketSize. And then still you will face >> problems if you have to handle a report that is larger than >> maxPacketSize. > > Like I said before, it depends on what your purpose is. > > For example, let's suppose your purpose is to process all the > report data > contained in a packet, and let's suppose that ReportSize < > wMaxPacketSize. > If you look at only the first ReportSize bytes then you will > process only > the first report. But if you look at all wMaxPacketSize bytes then > you > will process all the reports contained in the packet -- which > obviously is > what you want. > > Alan Stern > There is no situation where a USB device sends multiple reports in the same packet. -------------------------------------- Code Mercenaries Hard- und Software GmbH Karl-Marx-Str. 147a 12529 Schönefeld OT Grossziethen Germany Tel: x49-3379-2050920 Fax: x49-3379-2050930 HRB 16007 Potsdam Geschäftsführer: Guido Körber, Christian Lucht Did you subscribe to our Newsletter? If not, do so immediately by sending mail to: [email protected] Check out: www.codemercs.com ------------------------------------------------------------------------- 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 _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel