V4L/DVB (6979): tda18271: use a mutex to protect state in critical sections

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

2 files changed, 23 insertions, 0 deletions

diff --git a/drivers/media/dvb/frontends/tda18271-fe.c b/drivers/media/dvb/frontends/tda18271-fe.c
index c1da16ad07e7..e860f4c009c2 100644
--- a/drivers/media/dvb/frontends/tda18271-fe.c
+++ b/drivers/media/dvb/frontends/tda18271-fe.c
@@ -598,26 +598,36 @@ static int tda18271_init(struct dvb_frontend *fe)
 {
         struct tda18271_priv *priv = fe->tuner_priv;
 
+        mutex_lock(&priv->lock);
+
         /* initialization */
         tda18271_ir_cal_init(fe);
 
         if (priv->id == TDA18271HDC2)
                 tda18271_rf_cal_init(fe);
 
+        mutex_unlock(&priv->lock);
+
         return 0;
 }
 
 static int tda18271c2_tune(struct dvb_frontend *fe,
                            u32 ifc, u32 freq, u32 bw, u8 std)
 {
+        struct tda18271_priv *priv = fe->tuner_priv;
+
         tda_dbg("freq = %d, ifc = %d\n", freq, ifc);
 
         tda18271_init(fe);
 
+        mutex_lock(&priv->lock);
+
         tda18271_rf_tracking_filters_correction(fe, freq);
 
         tda18271_channel_configuration(fe, ifc, freq, bw, std);
 
+        mutex_unlock(&priv->lock);
+
         return 0;
 }
 
@@ -632,6 +642,8 @@ static int tda18271c1_tune(struct dvb_frontend *fe,
 
         tda18271_init(fe);
 
+        mutex_lock(&priv->lock);
+
         tda_dbg("freq = %d, ifc = %d\n", freq, ifc);
 
         /* RF tracking filter calibration */
@@ -766,6 +778,7 @@ static int tda18271c1_tune(struct dvb_frontend *fe,
 
         tda18271_write_regs(fe, R_TM, 15);
         msleep(5);
+        mutex_unlock(&priv->lock);
 
         return 0;
 }
@@ -1012,7 +1025,9 @@ static int tda18271_get_id(struct dvb_frontend *fe)
         char *name;
         int ret = 0;
 
+        mutex_lock(&priv->lock);
         tda18271_read_regs(fe);
+        mutex_unlock(&priv->lock);
 
         switch (regs[R_ID] & 0x7f) {
         case 3:
@@ -1065,6 +1080,7 @@ struct dvb_frontend *tda18271_attach(struct dvb_frontend *fe, u8 addr,
         priv->i2c_adap = i2c;
         priv->gate = (cfg) ? cfg->gate : TDA18271_GATE_AUTO;
         priv->cal_initialized = false;
+        mutex_init(&priv->lock);
 
         fe->tuner_priv = priv;
 
@@ -1084,8 +1100,12 @@ struct dvb_frontend *tda18271_attach(struct dvb_frontend *fe, u8 addr,
         if (tda18271_debug & DBG_MAP)
                 tda18271_dump_std_map(fe);
 
+        mutex_lock(&priv->lock);
+
         tda18271_init_regs(fe);
 
+        mutex_unlock(&priv->lock);
+
         return fe;
 fail:
         tda18271_release(fe);
diff --git a/drivers/media/dvb/frontends/tda18271-priv.h b/drivers/media/dvb/frontends/tda18271-priv.h
index b4d1ab770ca2..af89cfab0066 100644
--- a/drivers/media/dvb/frontends/tda18271-priv.h
+++ b/drivers/media/dvb/frontends/tda18271-priv.h
@@ -23,6 +23,7 @@
 
 #include <linux/kernel.h>
 #include <linux/types.h>
+#include <linux/mutex.h>
 #include "tda18271.h"
 
 #define R_ID     0x00   /* ID byte                */
@@ -112,6 +113,8 @@ struct tda18271_priv {
         struct tda18271_std_map std;
         struct tda18271_rf_tracking_filter_cal rf_cal_state[8];
 
+        struct mutex lock;
+
         u32 frequency;
         u32 bandwidth;
 };