On Mon, Apr 27, 2009 at 10:03 PM, Devin Heitmueller <devin.heitmueller@xxxxxxxxx> wrote: > Hello Janne, > > Ok, so now I need to better understand the nature of changeset 11356. > It turns up I spent the entire afternoon debugging a kernel panic on > usb disconnect, which ended up being due to this patch: > > au0828: use usb_interface.dev for v4l2_device_register > http://linuxtv.org/hg/v4l-dvb/rev/33810c734a0d > > The change to pass the interface->dev to v4l2_device_register() > effectively overwrote the interface data, so while I thought > usb_set_intfdata() was storing the au0828_dev *, in fact it was > holding a v4l2_device *. When au0828_usb_disconnect() eventually gets > called, the call to usb_get_intfdata() returned the v4l2_device, and > presto - instant panic. > > So, either I can roll back this change, or I can make the call to > usb_set_intfdata() *after* the call to v4l2_device_register(). > However, I don't know what else that might screw up (I haven't traced > out everything in v4l2-device that might expect a v4l2_device * to be > stored there). > > Suggestions? > > Perhaps if you could provide some additional background as to what > prompted this change, it will help me better understand the correct > course of action at this point. > > Devin > > cc: Robert Krakora and Josh Watzman since they both independently > reported what I believe to be the exact same issue (the stack is > slightly different because in their case as it crashed in the > dvb_unregister portion of the usb_disconnect routine). > > -- > Devin J. Heitmueller > http://www.devinheitmueller.com > AIM: devinheitmueller > Devin: I vote to roll it back until the ramifications of the changeset are better understood. ;-) Best Regards, -- Rob Krakora Senior Software Engineer MessageNet Systems 101 East Carmel Dr. Suite 105 Carmel, IN 46032 (317)566-1677 Ext. 206 (317)663-0808 Fax -- 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
