Hi Alan, > The device replied with a STALL. > The device runs at low speed or full speed and is connected through a USB-2 hub Yes, my device is full speed (12Mbps) device and connected to 2.0 root hub. So how to avoid getting the STALL? I attached the usbmon log and Ellisys USB analyser log. I connected the eight similar devices(USB Bluetooth Dongles) to host and captured the logs. My device numbers are here : Bus 001 Device Numbers (063\066\067\068\069\070\071\072) Usbmon log shows STALL packets for INT in URB completion handler $ tail -f /tmp/1.mon.out | grep "C Ii" ffff8800aaedb780 3159611663 C Ii:1:072:1 -32:1 0 ffff880131449cc0 3360277718 C Ii:1:068:1 -32:1 0 ffff8800aaedb9c0 3360278570 C Ii:1:069:1 -32:1 0 ffff880131f52000 3360291656 C Ii:1:067:1 -32:1 0 ffff8800aae88600 3360299542 C Ii:1:068:1 -32:1 0 On receiving the STALL response, work queue got scheduled in INT in URB completion handler for clearing halt condition(used usb_clear_halt() API in that work queue) I enabled “Drop Start of Frames and Keep Alives” & “Drop NAK transactions” recording options before taking the Ellisys USB analyser log. I don’t see STALL packet in Ellisys USB analyser log, but only observed in usbmon log. Does it mean, device is not sending the STALL, but only Host controller driver is sending it to my USB device driver? On Mon, Sep 29, 2014 at 7:01 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Mon, 29 Sep 2014, Naveen Kumar Parna wrote: > >> Hi All, >> >> I want to know the reason for getting INT urb completion status as -EPIPE ? > > The most common reasons are: > > The device replied with a STALL. > > The device runs at low speed or full speed and is connected > through a USB-2 hub. Under those conditions, URBs complete > with -EPIPE status when the device is disconnected. > > 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
