Re: patch usb-iowarrior.patch added to gregkh-2.6 tree
Alan Stern <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
On Wed, 21 Feb 2007, Guido Körber wrote: > Am 21.02.2007 um 16:31 schrieb Alan Stern: > > > On Wed, 21 Feb 2007, Guido Körber wrote: > > > >> But any device not following the specs will hit a wall with Windows > >> and MacOS as well. > > > > Don't be so sure. In Pete's case, the misbehaving device was a > > Microsoft > > keyboard! What makes you think Windows always implements the spec > > exactly? (Hint -- it doesn't.) > > I am very much aware of this. Sometimes if asked I tell people that > Windows does not have USB support... > > Though I still don't believe the thing about the keyboard, it makes > no sense. > > The majority of keyboardS is low speed USB, they can send no more > than 8 bytes per transfer. The standard keyboard report is exactly 8 > bytes long, so there is no chance of fitting two of them into the > same transfer. I don't understand it either. > Do you have any hard data on this thing? No. Maybe Pete can provide some. On the other hand, I did receive a report years ago that clearly showed a USB hub responding to an interrupt-IN request with more data bytes than necessary for the message it was sending. Obviously it was a bug in the hub's firmware. But I ended up changing the hub driver to accomodate it. > The situation we had was that our driver was requesting 8 bytes > (=maxPacketSize) but the device sends only 7 bytes (=reportSize) and > it did not work. > > Definitely the approach should be changed to using maxPacketSize as > well as ReportSize. Only these two combined can really tell you what > to do. Agreed. Alan Stern ------------------------------------------------------------------------- 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