On Wed, 17 Nov 2010 david.schueler@xxxxxxxxxxxxxxxxxxx wrote: > Ok, today i figured out that the "hang" appears on ftdi_close. So i enabled > "DETECT_HUNG_TASK" in ma kernel and got this: > Nov 17 11:51:51 Server [ 220.553322] drivers/usb/serial/ftdi_sio.c: > ftdi_close > Nov 17 11:54:11 Server [ 360.493081] INFO: task ws2500:7782 blocked for > more than 120 seconds. > Nov 17 11:54:11 Server [ 360.493083] "echo 0 > > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > Nov 17 11:54:11 Server [ 360.493085] ws2500 D 0000000000000001 > 5072 7782 6469 0x00000000 > Nov 17 11:54:11 Server [ 360.493090] ffff880081c19d08 0000000000000086 > ffffffff0000000f ffff88013f67adc0 > Nov 17 11:54:11 Server [ 360.493092] ffff880100000000 ffff880081c19fd8 > ffff88009a356320 0000000000013640 > Nov 17 11:54:11 Server [ 360.493095] ffff880081c19fd8 0000000000013640 > 0000000000013640 0000000000013640 > Nov 17 11:54:11 Server [ 360.493097] Call Trace: > Nov 17 11:54:11 Server [ 360.493104] [<ffffffff8136dc53>] usb_kill_urb > +0x91/0xaf > Nov 17 11:54:11 Server [ 360.493108] [<ffffffff810559ab>] ? > autoremove_wake_function+0x0/0x34 > Nov 17 11:54:11 Server [ 360.493113] [<ffffffffa01fe1b6>] ftdi_close > +0x4a/0x5e [ftdi_sio] > Nov 17 11:54:11 Server [ 360.493116] [<ffffffffa002402a>] serial_down > +0x2a/0x2c [usbserial] > Nov 17 11:54:11 Server [ 360.493119] [<ffffffff8127e36f>] > tty_port_shutdown+0x3d/0x4a > Nov 17 11:54:11 Server [ 360.493121] [<ffffffff8127e9c4>] tty_port_close > +0x1e/0x42 > Nov 17 11:54:11 Server [ 360.493124] [<ffffffffa00245ed>] serial_close > +0x58/0x61 [usbserial] > Nov 17 11:54:11 Server [ 360.493127] [<ffffffff81278314>] tty_release > +0x23e/0x5af > Nov 17 11:54:11 Server [ 360.493129] [<ffffffff8127d275>] ? > tty_ldisc_deref+0x9/0xb > Nov 17 11:54:11 Server [ 360.493131] [<ffffffff81278089>] ? tty_ioctl > +0x74f/0x76e > Nov 17 11:54:11 Server [ 360.493134] [<ffffffff81031391>] ? __wake_up > +0x3f/0x48 > Nov 17 11:54:11 Server [ 360.493137] [<ffffffff810de81b>] __fput > +0xf9/0x19b > Nov 17 11:54:11 Server [ 360.493139] [<ffffffff810de8d2>] fput+0x15/0x17 > Nov 17 11:54:11 Server [ 360.493141] [<ffffffff810dbbdf>] filp_close > +0x63/0x6d > Nov 17 11:54:11 Server [ 360.493143] [<ffffffff810dbc80>] sys_close > +0x97/0xcb > Nov 17 11:54:11 Server [ 360.493146] [<ffffffff8100296b>] > system_call_fastpath+0x16/0x1b > > But i dont know which function blocks (usb_kill_urb or > system_call_fastpath). > What do i have to investigate? usb_kill_urb() blocks. But investigating that function won't help, because it blocks waiting for the hardware. Clearly the problem lies in your nVidia chipset. If you want to delve deeper, make sure your kernel has CONFIG_USB_DEBUG and CONFIG_DEBUG_FS enabled. Mount a debugfs filesystem on /sys/kernel/debug. Then when the hang occurs, go into the appropriate subdirectory of /sys/kernel/debug/usb/ohci (the one corresponding to the controller your FTDI device is plugged into) and collect copies of the files there. 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
