tda18271: use a mutex to protect state in critical sections

From: Michael Krufky <mkrufky@linuxtv.org>

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>

2 files changed, 32 insertions, 0 deletions

diff --git a/linux/drivers/media/dvb/frontends/tda18271-fe.c b/linux/drivers/media/dvb/frontends/tda18271-fe.c
index 3af6ddb1b..26352716a 100644
--- a/linux/drivers/media/dvb/frontends/tda18271-fe.c
+++ b/linux/drivers/media/dvb/frontends/tda18271-fe.c
@@ -622,26 +622,36 @@ 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;
 }
 
@@ -655,6 +665,8 @@ static int tda18271c1_tune(struct dvb_frontend *fe,
 	u32 N = 0;
 
 	tda18271_init(fe);
+
+	mutex_lock(&priv->lock);
 #if 0
 	/* FIXME: FM Radio support */
 	if (t->mode == V4L2_TUNER_RADIO)
@@ -795,6 +807,7 @@ static int tda18271c1_tune(struct dvb_frontend *fe,
 
 	tda18271_write_regs(fe, R_TM, 15);
 	msleep(5);
+	mutex_unlock(&priv->lock);
 
 	return 0;
 }
@@ -1051,7 +1064,9 @@ 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:
@@ -1104,6 +1119,7 @@ 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;
 
@@ -1123,8 +1139,12 @@ 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/linux/drivers/media/dvb/frontends/tda18271-priv.h b/linux/drivers/media/dvb/frontends/tda18271-priv.h
index b4d1ab770..5eaa0462b 100644
--- a/linux/drivers/media/dvb/frontends/tda18271-priv.h
+++ b/linux/drivers/media/dvb/frontends/tda18271-priv.h
@@ -23,6 +23,12 @@
 
 #include <linux/kernel.h>
 #include <linux/types.h>
+#include "compat.h"
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
+#include <linux/mutex.h>
+#else
+#include <asm/semaphore.h>
+#endif
 #include "tda18271.h"
 
 #define R_ID     0x00	/* ID byte                */
@@ -112,6 +118,12 @@ struct tda18271_priv {
 	struct tda18271_std_map std;
 	struct tda18271_rf_tracking_filter_cal rf_cal_state[8];
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
+	struct mutex lock;
+#else
+	struct semaphore lock;
+#endif
+
 	u32 frequency;
 	u32 bandwidth;
 };