Bitstuff: the USB protocol restricts how many ones/zeros may be consecutively sent down the wire. Details in the spec, the basic idea is (as I recall) to make sure that no data can cause a signal pattern that looks much like the ones used to delimit packets, frames, and such.
PID problem: PID is a field in the USB packet. USB_PID_* in <linux/usb.h> ... examples are IN, OUT, DATA0, DATA1. I don't have time to track this down further (look at the OHCI and USB specs, and debug!) but if the HC got the wrong PID, or an illegal one, that should appear. - Dave ----- Original Message ----- From: "Matthew Dharm" <[EMAIL PROTECTED]> To: "David Brownell" <[EMAIL PROTECTED]> Cc: "Björn Stenberg" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Thursday, December 06, 2001 2:05 PM Subject: Re: [linux-usb-devel] Error -71 (fwd) What, exactly, is a "bitstuff error" and "PID problems"? Matt On Thu, Dec 06, 2001 at 01:41:05PM -0800, David Brownell wrote: > > Error -71 is EPROTO, but why do I get it all of a sudden? The only places I > > see it returned in the code are in uhci.c and usb-uhci.c. But this is OHCI... > > The current "usb-ohci.c" uses the <linux/usb.h> USB_ST_* macros, > which use EPROTO for USB_ST_BITSTUFF and in one other > place that OHCI doesn't trigger. > > In drivers/usb/usb-ohci.h I see USB_ST_BITSTUFF for three errors > that the hardware reports -- bitstuffing errors and PID problems. > > Unclear why you get it "all of a sudden". > > - Dave > _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
