On Sun, Nov 6, 2016 at 7:40 AM, Jörg Otte <jrg.otte@xxxxxxxxx> wrote: > Since v4.9-rc4 I get following crash in dvb-usb-cinergyT2 module. Looks like it's commit 5ef8ed0e5608f ("[media] cinergyT2-core: don't do DMA on stack"), which movced the DMA data array from the stack to the "private" pointer. In the process it also added serialization in the form of "data_mutex", but and now it oopses on that mutex because the private pointer is NULL. It looks like the "->private" pointer is allocated in dvb_usb_adapter_init() cinergyt2_usb_probe -> dvb_usb_device_init -> dvb_usb_init() -> dvb_usb_adapter_init() but the dvb_usb_init() function calls dvb_usb_device_power_ctrl() (which calls the "power_ctrl" function, which is cinergyt2_power_ctrl() for that drive) *before* it initializes the private field. Mauro, Patrick, could dvb_usb_adapter_init() be called earlier, perhaps? Linus -- 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