On Tue, 25 Sep 2012, Greg KH wrote: > On Tue, Sep 25, 2012 at 04:57:43PM +0400, Andrew wrote: > > Uwe Bonnes писал 25.09.2012 12:46: > > >>>>>>"Andrew" == Andrew <andrew@xxxxxxxxxx> writes: > > > > > > Andrew> This is seen on widely used ftdi ft232rl chips. > > >Setting the > > > Andrew> parity to something like 'even' results in occasional > > >framing > > > Andrew> errors when transmitting data. > > > > > > Andrew> Relevant timing diagrams from the logic analyzer are > > >attached to > > > Andrew> this bug: > > >https://bugzilla.kernel.org/show_bug.cgi?id=47921 > > > > > >Is this a driver or a hardware thing? > > > > I think that this is a driver problem, since windows drivers do not > > produce any framing errors. > > I stumbled upon this while reversing the STC microcontroller ISP > > protocol that happen to use 'even' parity. > > I can send in more timing diagrams both from windows and linux hosts > > to compare. > > I don't see how the ftdi device can change the timings of the signals by > the USB side at all, do you? That implies that it couldn't be the > driver as it has no control over this type of thing. > > Or am I missing something from the device spec somewhere? It might be a good idea to compare a usbmon trace with an equivalent record from a Windows system. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
