On Thu, Nov 03, 2011 at 12:10:50PM -0400, Alan Stern wrote: > On Thu, 3 Nov 2011, Greg KH wrote: > > > On Thu, Nov 03, 2011 at 11:46:48AM -0400, Nick Bowler wrote: > > > On 2011-11-03 08:35 -0700, Greg KH wrote: > > > > On Thu, Nov 03, 2011 at 10:47:16AM -0400, Nick Bowler wrote: > > > > > pl2303_break_ctl - error sending break = -32 > > > > > > > > > > -32 would appear to be EPIPE. With the debugging disabled these errors > > > > > get dropped on the floor, hence everything seems normal except that > > > > > nothing happens when I send a break. The adaptor seems to work > > > > > fine otherwise. > > > > > > > > That means your device does not support the "set break" command, sorry. > > > > > > > > I suggest you use a "real" usb to serial device, and not this one, if > > > > you need to send a break with it. The pl2303 device is barely a > > > > workable serial device, in my opinion of working with it for years. > > > > There are many other better devices out there (like the ftdi_sio > > > > devices for one.) > > > > > > OK, fair enough. > > > > > > Perhaps this driver could print an error message to that effect, then, > > > instead of remaining completely silent? If EPIPE means "not supported", > > > I can cook something up. > > > > Wait, -EPIPE is odd, that usually means the driver messed up in trying > > to send a message to the wrong endpoint. Yet this is going through the > > control endpoint, which really can't fail. > > -EPIPE also means that the control endpoint doesn't recognize the > command it received, which seems quite likely in this case. Ah, ok, someone needs to update Documentation/usb/error-codes.txt then :) So, this makes sense, this device has no idea how to create a BREAK command, not much we can do about it, especially given the total lack of documentation from Prolific for this chipset. Again, I recommend buying a new device. greg k-h -- 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
