<div dir="ltr">Thanks for the reply Bjorn and Mark. Looks like the AC314U ttyUSB[0-2] none of them responds to AT commands. So I cant say what AT+CSQ would have said at that point .. The modems display says "disconnected" .. I will try to see if I can reset the USB bus and recover from that in a "automated" fashion. Rgds, Gopa. </div><div class="gmail_extra"> <div class="gmail_quote">On Tue, Oct 28, 2014 at 1:20 AM, Markus Gothe <<a href="mailto:nietzsche@lysator.liu.se" target="_blank">nietzsche@lysator.liu.se</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Did you check what your CSQ (AT+CSQ) is when receiving the error? //M Skickat ifrån min mobil. Den 28 okt 2014 06:17 skrev Gopakumar Choorakkot Edakkunni <<a href="mailto:gopakumar.c.e@gmail.com">gopakumar.c.e@gmail.com</a>>: > > Hi QMI experts, > > I have an AC 340U modem for which I periodically monitor the signal strength using the qmicli below. At times when my signal strength drop badly down to zero, I see that qmicli spits out the below errors continuosly. I did a google and saw some discussions around the EPIPE error, but none around EPROTO. Any thoughts/comments/suggestions would be very helpful ! > > qmicli -d </dev/...> --nas-get-signal-info > > <logs> > qmi_wwan 1-1.3:1.8: nonzero urb status received: -71 (-71 == EPROTO) > qmi_wwan 1-1.3:1.8: wdm_int_callback - 0 bytes > qmi_wwan 1-1.3:1.8: nonzero urb status received: -71 > qmi_wwan 1-1.3:1.8: wdm_int_callback - 0 bytes > > Rgds, > Gopa. > > > </blockquote></div> </div>