V4L/DVB (13976): [STV090x] Added mutex protection around tuner I2C access.

With this change it is possible to have the same I2C address for both tuners.

Signed-off-by: Andreas Regel <andreas.regel@gmx.de>
Signed-off-by: Manu Abraham <manu@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

2 files changed, 10 insertions, 0 deletions

diff --git a/drivers/media/dvb/frontends/stv090x.c b/drivers/media/dvb/frontends/stv090x.c
index 9a817a69ed30..e903334a8323 100644
--- a/drivers/media/dvb/frontends/stv090x.c
+++ b/drivers/media/dvb/frontends/stv090x.c
@@ -758,6 +758,9 @@ static int stv090x_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
         struct stv090x_state *state = fe->demodulator_priv;
         u32 reg;
 
+        if (enable)
+                mutex_lock(&state->internal->tuner_lock);
+
         reg = STV090x_READ_DEMOD(state, I2CRPT);
         if (enable) {
                 dprintk(FE_DEBUG, 1, "Enable Gate");
@@ -771,9 +774,14 @@ static int stv090x_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
                 if ((STV090x_WRITE_DEMOD(state, I2CRPT, reg)) < 0)
                         goto err;
         }
+
+        if (!enable)
+                mutex_unlock(&state->internal->tuner_lock);
+
         return 0;
 err:
         dprintk(FE_ERROR, 1, "I/O error");
+        mutex_unlock(&state->internal->tuner_lock);
         return -1;
 }
 
@@ -4439,6 +4447,7 @@ struct dvb_frontend *stv090x_attach(const struct stv090x_config *config,
         }
 
         mutex_init(&state->internal->demod_lock);
+        mutex_init(&state->internal->tuner_lock);
 
         if (stv090x_sleep(&state->frontend) < 0) {
                 dprintk(FE_ERROR, 1, "Error putting device to sleep");
diff --git a/drivers/media/dvb/frontends/stv090x_priv.h b/drivers/media/dvb/frontends/stv090x_priv.h
index d38542665b0a..5b780c80d496 100644
--- a/drivers/media/dvb/frontends/stv090x_priv.h
+++ b/drivers/media/dvb/frontends/stv090x_priv.h
@@ -235,6 +235,7 @@ struct stv090x_internal {
         u8                      i2c_addr;
 
         struct mutex            demod_lock; /* Lock access to shared register */
+        struct mutex            tuner_lock; /* Lock access to tuners */
         s32                     mclk; /* Masterclock Divider factor */
         u32                     dev_ver;