On Mon, 2 Feb 2009 kilgota@xxxxxxxxxxxxxxxxxxxxxx wrote: > The attached file is an extract from dmesg from the Pentium4 Dual Core > machine. One can see that the camera has been attached, and then an svv > session has been run. The kernel is the "stock" Slackware 2.6.27.7 kernel > (*). We have a situation, again, in which svv (**) can not be exited. We > have an oops in the log, and we have a filesystem check on reboot, which > is going on as I write this. Well, the problem is clear enough, and it is in the gspca.c module, not your sq905-3 driver. I'm not sure what the best way is to fix it, so I'm CC'ing the people responsible for the gspca driver. To summarize: Unplugging the camera while it is in use by a program causes an oops (particularly on an SMP machine). The problem is that gspca_stream_off() calls destroy_urbs(), which in turn calls usb_buffer_free() -- but this happens too late, after gspca_disconnect() has returned. By that time gspca_dev->dev is a stale pointer, so it shouldn't be passed to usb_buffer_free(). What should happen is that as part of disconnect processing, the existing stream(s) should be put in an error state and destroy_urbs() should be called immediately. Then when gspca_stream_off() calls destroy_urbs() again there would be no more work left to do. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
