On Tuesday 31 August 2004 12:50 pm, Alan Stern wrote: > > Anyway, could anyone comment on the problem I discovered ? > > Could it be a UHCI/root hub problem ? Or is it certain that the > > device is faulty ? If the device is faulty, what should be done ? > > Could the buffer size be lowered from > > 9 to 8, or is it against the kernel policies to make such a change for a > > broken device ? > > It's certainly not the kernel's fault. And the buffer size cannot be > lowered back to 8, as raising it to 9 was necessary to work with other > (slightly broken) devices. > > Another possibility is to increase the buffer to 64 bytes.
Or to lower it to 4 bytes ... I was going to send in a patch that did that, but the 9 byte patch went in first. The config descriptor's full size is bytes index 2 and 3 in the buffer. A 4 byte request forces a short read in the same way 9 bytes does, but 8 bytes does not. And a 9 byte request is prone to two different families of boundary case bugs: 8 byte boundary for packet size, and 10 byte boundary for the next descriptor in the group. - Dave ------------------------------------------------------- This SF.Net email is sponsored by BEA Weblogic Workshop FREE Java Enterprise J2EE developer tools! Get your free copy of BEA WebLogic Workshop 8.1 today. http://ads.osdn.com/?ad_id=5047&alloc_id=10808&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
