dmesg 
[334733.681216] quickcam [22.620525]: open users=1
[334733.775801] quickcam [22.715306]: qc_sensor_init: call qc_sensor_setsize0 (324,248)
[334733.778791] quickcam [22.718305]: set sensor=324x248 vwin=320x240
[334733.811766] quickcam [22.751346]: VIDIOCGWIN: 320,240
[334733.811881] quickcam [22.751464]: VIDIOCSWIN: call qc_sensor_setsize 160,120
[334733.814763] quickcam [22.754351]: set sensor=162x124 vwin=160x112
[334733.814887] quickcam [22.754475]: VIDIOCGWIN: 160,112
[334734.191833] quickcam [23.132201]: submit ISOC_URB 0 failed
[334734.191840] quickcam [23.132211]: failed qc_isoc_init()=-28
[334734.191843] quickcam: unable start isoc
[334734.191846] quickcam [23.132217]: failed qc_capt_get()=-28
[334734.191849] quickcam [23.132219]: failed qc_v4l_ioctl()=-28
[334736.258324] quickcam [25.202979]: close users=0
[334765.897484] quickcam [54.903628]: open users=1
[334765.991764] quickcam [54.998103]: qc_sensor_init: call qc_sensor_setsize0 (324,248)
[334765.994760] quickcam [55.001106]: set sensor=324x248 vwin=320x240
[334766.027730] quickcam [55.034144]: VIDIOCGWIN: 320,240
[334766.027737] quickcam [55.034153]: VIDIOCSWIN: call qc_sensor_setsize 160,120
[334766.030680] quickcam [55.037102]: set sensor=162x124 vwin=160x112
[334766.030686] quickcam [55.037109]: VIDIOCGWIN: 160,112
[334828.378740] quickcam [57.514506]: wait_event_interruptible() returned ERESTARTSYS
[334828.378746] quickcam [57.514514]: failed qc_frame_get()=-512
[334828.378749] quickcam [57.514518]: retrying failed qc_frame_get... rounds=8
[334828.378752] quickcam [57.514520]: break: retrycount=8 r=-512
[334828.378754] quickcam [57.514523]: failed qc_capt_get()=-512
[334828.378757] quickcam [57.514526]: failed qc_v4l_ioctl()=-512
[334830.799582] quickcam [59.940369]: close users=0
[334830.802882] quickcam [59.943677]: Not streaming/connected anymore. Ignoring isoc interrupt, dev=c76f4800 streaming=0 status=-2
[334830.803881] quickcam [59.944678]: Not streaming/connected anymore. Ignoring isoc interrupt, dev=c76f4800 streaming=0 status=-2