[PATCH 01/13] [media] dvb-frontends/stv0367: add flag to make i2c_gatectrl optional

[Daniel Scheller <d.scheller.oss@gmail.com>]

From: Daniel Scheller <d.scheller@gmx.net>

There can be use cases (bridges, namely ddbridge) which will care about
gate control in a way that involves mutex_locks and remapped i2c_gatectrl
FE ops. If the demod driver (additionally) performs it's own gate control
and there's something else that already took the lock, locking again will
lead to kernel deadlocks, so add and check a conditional before triggering
gate_ctrl.

Signed-off-by: Daniel Scheller <d.scheller@gmx.net>
---
 drivers/media/dvb-frontends/stv0367.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/media/dvb-frontends/stv0367.c b/drivers/media/dvb-frontends/stv0367.c
index fd49c43..fc80934 100644
--- a/drivers/media/dvb-frontends/stv0367.c
+++ b/drivers/media/dvb-frontends/stv0367.c
@@ -89,6 +89,8 @@ struct stv0367_state {
 	struct stv0367cab_state *cab_state;
 	/* DVB-T */
 	struct stv0367ter_state *ter_state;
+	/* flags for operation control */
+	u8 use_i2c_gatectrl;
 };
 
 struct st_register {
@@ -1827,10 +1829,10 @@ static int stv0367ter_set_frontend(struct dvb_frontend *fe)
 	stv0367ter_init(fe);
 
 	if (fe->ops.tuner_ops.set_params) {
-		if (fe->ops.i2c_gate_ctrl)
+		if (state->use_i2c_gatectrl && fe->ops.i2c_gate_ctrl)
 			fe->ops.i2c_gate_ctrl(fe, 1);
 		fe->ops.tuner_ops.set_params(fe);
-		if (fe->ops.i2c_gate_ctrl)
+		if (state->use_i2c_gatectrl && fe->ops.i2c_gate_ctrl)
 			fe->ops.i2c_gate_ctrl(fe, 0);
 	}
 
@@ -2321,6 +2323,9 @@ struct dvb_frontend *stv0367ter_attach(const struct stv0367_config *config,
 	state->fe.demodulator_priv = state;
 	state->chip_id = stv0367_readreg(state, 0xf000);
 
+	/* demod operation options */
+	state->use_i2c_gatectrl = 1;
+
 	dprintk("%s: chip_id = 0x%x\n", __func__, state->chip_id);
 
 	/* check if the demod is there */
@@ -3120,10 +3125,10 @@ static int stv0367cab_set_frontend(struct dvb_frontend *fe)
 
 	/* Tuner Frequency Setting */
 	if (fe->ops.tuner_ops.set_params) {
-		if (fe->ops.i2c_gate_ctrl)
+		if (state->use_i2c_gatectrl && fe->ops.i2c_gate_ctrl)
 			fe->ops.i2c_gate_ctrl(fe, 1);
 		fe->ops.tuner_ops.set_params(fe);
-		if (fe->ops.i2c_gate_ctrl)
+		if (state->use_i2c_gatectrl && fe->ops.i2c_gate_ctrl)
 			fe->ops.i2c_gate_ctrl(fe, 0);
 	}
 
@@ -3437,6 +3442,9 @@ struct dvb_frontend *stv0367cab_attach(const struct stv0367_config *config,
 	state->fe.demodulator_priv = state;
 	state->chip_id = stv0367_readreg(state, 0xf000);
 
+	/* demod operation options */
+	state->use_i2c_gatectrl = 1;
+
 	dprintk("%s: chip_id = 0x%x\n", __func__, state->chip_id);
 
 	/* check if the demod is there */
-- 
2.10.2