On Fri, Jan 22, 2010 at 1:23 PM, Manu Abraham <abraham.manu@xxxxxxxxx> wrote: > The point there is that it is a dual demod which implements a FSM for > it's tuner flow control and hence. The demodulators in the tree are > generally single/standalone and don't need such a FSM to handle that. > Even if it's a dual frontend, most of them just do locking for the > register access, while here it is not register access locking, while > it is controlling state, similar to Finite State Machine (FSM) Ok, I see what is going on now. I didn't notice before that the gate enable was keeping the "state->internal->tuner_lock" mutex set even after the call returned. My only concern here then is that I've seen cases where the i2c_gate_ctrl() function is called in a non-symmetric fashion (where the enable/disable calls are not necessarily properly balanced), depending on the driver. While I am relatively confident that you have balanced the instances where it is called within your driver, I would be concerned about how it could possibly be called from other places such as from the tuner driver or the dvb frontend core. Today, there is no real problem if a particular call path attempts to enable the gate if it is already open (or disable if it is already closed). With your proposed change, you will result in a deadlock. Also, you might want to consider replacing the calls themselves with "fe->ops.i2c_gate_ctrl()" as opposed to calling the internal function directly, since that will allow the "frontend ioctl override" framework to continue to work properly. Devin -- Devin J. Heitmueller - Kernel Labs http://www.kernellabs.com -- 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
