Hi Mauro, Following the discussion we had today on IRC, here's a proof of concept patch that fixes the reference counting bug in the em28xx driver with the PCTV 520E. The problem was noticed when the tuner driver was missing. The error handling code path tried to free the frontend by calling dvb_frontend_detach(), which can't operate properly if the frontend refcount field hasn't been initialized yet. This is a proof of concept only as it doesn't patch all frontend drivers to call the dvb_frontend_init() function. You might also want to avoid bisection problems, and possibly bikeshed function names. You could also add a Fixes tag somewhere referencing commit 1f862a68df2449bc7b1cf78dce616891697b4bdf Author: Max Kellermann <max.kellermann@xxxxxxxxx> Date: Tue Aug 9 18:32:51 2016 -0300 [media] dvb_frontend: move kref to struct dvb_frontend although I think the problem preexisted that commit under another form. Laurent Pinchart (3): dvb_frontend: Rename the dvb_frontend_init() function dvb_frontend: Add dvb_frontend_init() function media: drxk: Initialize the frontend after allocating it drivers/media/dvb-core/dvb_frontend.c | 50 ++++++++++++++++++++------------- drivers/media/dvb-core/dvb_frontend.h | 11 ++++++++ drivers/media/dvb-frontends/drxk_hard.c | 5 ++++ 3 files changed, 46 insertions(+), 20 deletions(-) -- Regards, Laurent Pinchart
