Re: Panic in HVR-950q caused by changeset 11356
On Mon, Apr 27, 2009 at 10:03 PM, Devin Heitmueller devin.heitmuel...@gmail.com 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 majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Panic in HVR-950q caused by changeset 11356
On Tue, Apr 28, 2009 at 12:42 PM, Robert Krakora rob.krak...@gmail.com wrote: Devin: I vote to roll it back until the ramifications of the changeset are better understood. ;-) Best Regards, Robert, I discussed it at length with Janneg on #linuxtv this morning. A pull request has been submitted with the fix, marked high priority. Thanks, Devin -- Devin J. Heitmueller http://www.devinheitmueller.com AIM: devinheitmueller -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Panic in HVR-950q caused by changeset 11356
Devin Heitmueller wrote: I discussed it at length with Janneg on #linuxtv this morning. A pull request has been submitted with the fix, marked high priority. I just pulled and built from the main hg tree, and in a simple test it did not oops on disconnect! Thanks for everyone's work, and I'll continue to test over the next week or so and let you know if it happens again. (Also, thanks for the CC, and please continue to do so on anything related to this issue; I unsubscribed from the list a few days ago due to the relatively high traffic.) Josh Watzman -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Panic in HVR-950q caused by changeset 11356
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 -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
