I'm polling a couple of input bits as well as 16 bit memory registers from a PLC (xinje) using libmodbus. Feb 23 09:59:34 localhost kernel: [16960.073287] usb 5-1: USB disconnect, device number 11 Feb 23 09:59:34 localhost kernel: [16960.080069] usb 5-1: pl2303_read_int_callback - usb_submit_urb failed with result -19 Feb 23 09:59:35 localhost kernel: [16960.426637] usb 5-1: new full-speed USB device number 12 using sw-ohci Feb 23 09:59:35 localhost kernel: [16960.649900] usb 5-1: pl2303 converter now attached to ttyUSB10 Feb 23 09:59:35 localhost mtp-probe: checking bus 5, device 12: "/sys/devices/platform/sw-ohci.2/usb5/5-1" Feb 23 10:26:18 localhost kernel: [18563.802940] usb 5-1: USB disconnect, device number 12 Feb 23 10:26:18 localhost kernel: [18563.809722] usb 5-1: pl2303_read_int_callback - usb_submit_urb failed with result -19 Feb 23 10:26:18 localhost kernel: [18564.155245] usb 5-1: new full-speed USB device number 13 using sw-ohci Feb 23 10:26:19 localhost kernel: [18564.387584] usb 5-1: pl2303 converter now attached to ttyUSB11 Feb 23 10:26:19 localhost mtp-probe: checking bus 5, device 13: "/sys/devices/platform/sw-ohci.2/usb5/5-1" Feb 23 10:38:53 localhost kernel: [19319.217576] usb 5-1: USB disconnect, device number 13 Feb 23 10:38:53 localhost kernel: [19319.229452] usb 5-1: pl2303_read_int_callback - usb_submit_urb failed with result -19 Feb 23 10:38:54 localhost kernel: [19319.572229] usb 5-1: new full-speed USB device number 14 using sw-ohci Feb 23 10:38:54 localhost kernel: [19319.812946] usb 5-1: pl2303 converter now attached to ttyUSB12 Any pointers for a workaround at the driver level? I could see that ENODEV results with the wrong device status. could that status be device 'busy'? will it help if i reduce my polling rate? Thanks, Malith On Tue, Jul 5, 2016 at 6:09 PM Johan Hovold <johan@xxxxxxxxxx> wrote: > > On Mon, Jul 04, 2016 at 10:22:04PM +0530, Malith Yapa wrote: > > Continuously polling registers with the PL2303 usb serial adapter > > eventually results in usb_subimit_urb failed with result -19 (ENODEV) > > but reconnects immediately. > > occurrences are random. > > tried with two different PL2303 devices with the same result. > > Sounds like a firmware issue, so not sure there's much we can do. > > Can you tell from the syslogs that the device is being disconnected and > re-enumerated? What registers are you polling? > > Thanks, > Johan -- 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
