We are using sierra modem for 4G LTE networks. we used to communicate with modem using AT commands via ttyUSB ports. Recently we observed a crash in usb driver interface when we try to post some AT commands. After the crash the kernel seems to be hanged. We were not able to execute any commands or open a new tty terminal. Even reboot command was not working fine. The system went to completely unusable/unstable state. It recovered only after hard reboot. Nov 30 18:59:01 ATCMD = [AT+CMEE=2] Nov 30 18:59:02 [AT_TRX]Garbage cleared Nov 30 18:59:02 [AT_TRX]Data from Stream --> [OK] Nov 30 18:59:02 [AT_TRX]Poll Ended Nov 30 18:59:02 [AT_TRX]Result :[-1] Nov 30 18:59:02 [AT_TRX]Garbage cleared Nov 30 18:59:02 kernel: [19926.147811] usb 2-1.3: USB disconnect, device number 126 Nov 30 18:59:02 kernel: [19926.147985] sierra ttyUSB0: Sierra USB modem converter now disconnected from ttyUSB0 Nov 30 18:59:02 kernel: [19926.148002] sierra 2-1.3:1.0: device disconnected Nov 30 18:59:02 kernel: [19926.148127] sierra ttyUSB1: Sierra USB modem converter now disconnected from ttyUSB1 Nov 30 18:59:02 kernel: [19926.148138] sierra 2-1.3:1.1: device disconnected Nov 30 18:59:02 kernel: [19926.150070] sierra ttyUSB2: sierra_submit_rx_urbs: submit urb failed: -19 Nov 30 18:59:02 kernel: [19926.152626] sierra ttyUSB2: sierra_submit_rx_urbs: submit urb failed: -19 Nov 30 18:59:02 kernel: [19926.155136] sierra ttyUSB2: sierra_submit_rx_urbs: submit urb failed: -19 Nov 30 18:59:02 kernel: [19926.157589] sierra ttyUSB2: sierra_submit_rx_urbs: submit urb failed: -19 Nov 30 18:59:02 kernel: [19926.159999] sierra ttyUSB2: sierra_submit_rx_urbs: submit urb failed: -19 Nov 30 18:59:02 kernel: [19926.162438] sierra ttyUSB2: sierra_submit_rx_urbs: submit urb failed: -19 Nov 30 18:59:02 kernel: [19926.164870] sierra ttyUSB2: sierra_submit_rx_urbs: submit urb failed: -19 Nov 30 19:01:12 kernel: [20056.174514] INFO: task khubd:369 blocked for more than 120 seconds. Nov 30 19:01:12 kernel: [20056.176931] Tainted: G O 3.12.0.custom-1.3 #2 Nov 30 19:01:12 kernel: [20056.179297] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Nov 30 19:01:12 kernel: [20056.181648] khubd D ffff880409a3f3c8 0 369 2 0x00000000 Nov 30 19:01:12 kernel: [20056.181653] ffff880409a3f0c0 0000000000000046 0000000000000000 ffff88040b573780 Nov 30 19:01:12 kernel: [20056.181655] ffff880032f1ffd8 ffff880032f1ffd8 ffff880032f1ffd8 ffff880409a3f0c0 Nov 30 19:01:12 kernel: [20056.181657] 0000000080000000 ffff88035aafc9e8 ffff88035aafc9ec ffff880409a3f0c0 Nov 30 19:01:12 kernel: [20056.181660] Call Trace: Nov 30 19:01:12 kernel: [20056.181667] [<ffffffff814ef199>] ? schedule_preempt_disabled+0x9/0x10 Nov 30 19:01:12 kernel: [20056.181670] [<ffffffff814ed4f1>] ? __mutex_lock_slowpath+0x141/0x1c0 Nov 30 19:01:12 kernel: [20056.181673] [<ffffffff814ed586>] ? mutex_lock+0x16/0x30 Nov 30 19:01:12 kernel: [20056.181685] [<ffffffffa0106f4e>] ? usb_serial_disconnect+0x2e/0x120 [usbserial] Nov 30 19:01:12 kernel: [20056.181699] [<ffffffffa01271aa>] ? usb_unbind_interface+0x6a/0x1c0 [usbcore] Nov 30 19:01:12 kernel: [20056.181705] [<ffffffff81394be9>] ? __device_release_driver+0x79/0xf0 Nov 30 19:01:12 kernel: [20056.181707] [<ffffffff81393100>] ? bus_get_device_klist+0x10/0x10 Nov 30 19:01:12 kernel: [20056.181709] [<ffffffff81394e55>] ? device_release_driver+0x25/0x40 Nov 30 19:01:12 kernel: [20056.181712] [<ffffffff81394672>] ? bus_remove_device+0xf2/0x140 Nov 30 19:01:12 kernel: [20056.181714] [<ffffffff81391a25>] ? device_del+0x115/0x1a0 Nov 30 19:01:12 kernel: [20056.181722] [<ffffffffa0124e34>] ? usb_disable_device+0x94/0x1d0 [usbcore] Nov 30 19:01:12 kernel: [20056.181728] [<ffffffffa011c4ee>] ? usb_disconnect+0x8e/0x190 [usbcore] Nov 30 19:01:12 kernel: [20056.181734] [<ffffffffa011dc02>] ? hub_thread+0x422/0x1380 [usbcore] Nov 30 19:01:12 kernel: [20056.181738] [<ffffffff814edf9e>] ? __schedule+0x2de/0x770 Nov 30 19:01:12 kernel: [20056.181740] [<ffffffff8107d730>] ? finish_wait+0x90/0x90 Nov 30 19:01:12 kernel: [20056.181747] [<ffffffffa011d7e0>] ? hub_port_debounce+0xe0/0xe0 [usbcore] Nov 30 19:01:12 kernel: [20056.181750] [<ffffffff8107cfd3>] ? kthread+0xb3/0xc0 Nov 30 19:01:12 kernel: [20056.181753] [<ffffffff81080000>] ? hrtimer_get_remaining+0x20/0x50 Nov 30 19:01:12 kernel: [20056.181756] [<ffffffff8107cf20>] ? kthread_create_on_node+0x110/0x110 Nov 30 19:01:12 kernel: [20056.181758] [<ffffffff814f7e0c>] ? ret_from_fork+0x7c/0xb0 Nov 30 19:01:12 kernel: [20056.181761] [<ffffffff8107cf20>] ? kthread_create_on_node+0x110/0x110 Regards, Saravanan N -- 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
