Oliver, > That's odd. I can't tell from the log. Can you make a usbmon trace? sure: cat /sys/kernel/debug/usbmon/1u ffff880088545300 2462700154 S Ii:1:006:1 -115:8 8 < ffff8800884b2600 2462700171 S Co:1:006:0 s 21 22 0003 0000 0000 0 ffff8800884b2600 2462701898 C Co:1:006:0 0 0 ffff880088545240 2462702064 S Bo:1:006:7 -115 6 = 060a0000 0000 ffff880088545900 2462702133 S Bi:1:006:2 -115 128 < ffff880088545cc0 2462702142 S Bi:1:006:2 -115 128 < ffff880088545600 2462702146 S Bi:1:006:2 -115 128 < ffff8800885450c0 2462702150 S Bi:1:006:2 -115 128 < ffff8800885453c0 2462702154 S Bi:1:006:2 -115 128 < ffff880088545480 2462702158 S Bi:1:006:2 -115 128 < ffff880088545180 2462702162 S Bi:1:006:2 -115 128 < ffff8800885456c0 2462702166 S Bi:1:006:2 -115 128 < ffff880088545540 2462702170 S Bi:1:006:2 -115 128 < ffff880088545000 2462702174 S Bi:1:006:2 -115 128 < ffff8800885459c0 2462702179 S Bi:1:006:2 -115 128 < ffff880088545840 2462702183 S Bi:1:006:2 -115 128 < ffff880088545f00 2462702187 S Bi:1:006:2 -115 128 < ffff880088545c00 2462702191 S Bi:1:006:2 -115 128 < ffff880088545b40 2462702199 S Bi:1:006:2 -115 128 < ffff880088545a80 2462702202 S Bi:1:006:2 -115 128 < this is where it hangs on poll(). then I press CTRL-C for the application, then I get: ffff88007c8e2b40 2502550672 S Co:1:006:0 s 21 22 0000 0000 0000 0 ffff88007c8e2b40 2502552140 C Co:1:006:0 0 0 ffff880088545300 2502553133 C Ii:1:006:1 -2:8 0 ffff880088545240 2502554132 C Bo:1:006:7 -2 0 ffff880088545a80 2502555132 C Bi:1:006:2 -2 0 ffff880088545b40 2502556132 C Bi:1:006:2 -2 0 ffff880088545c00 2502557132 C Bi:1:006:2 -2 0 ffff880088545f00 2502558132 C Bi:1:006:2 -2 0 ffff880088545840 2502559132 C Bi:1:006:2 -2 0 ffff8800885459c0 2502560131 C Bi:1:006:2 -2 0 ffff880088545000 2502561130 C Bi:1:006:2 -2 0 ffff880088545540 2502562126 C Bi:1:006:2 -2 0 ffff8800885456c0 2502563132 C Bi:1:006:2 -2 0 ffff880088545180 2502564131 C Bi:1:006:2 -2 0 ffff880088545480 2502565130 C Bi:1:006:2 -2 0 ffff8800885453c0 2502566125 C Bi:1:006:2 -2 0 ffff8800885450c0 2502567134 C Bi:1:006:2 -2 0 ffff880088545600 2502568134 C Bi:1:006:2 -2 0 ffff880088545cc0 2502569134 C Bi:1:006:2 -2 0 ffff880088545900 2502570134 C Bi:1:006:2 -2 0 Akos -- 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