We need own I2C locking because of tuner I2C adapter/repeater.
Firmware command is executed using I2C send + reply message. Default
I2C adapter locking protects only single I2C operation, not whole
send + reply sequence as needed. Due to that, it was possible tuner
I2C message interrupts firmware command sequence.
Reported-by: Adam Baker <linux@xxxxxxxxxxxxxxxx>
Signed-off-by: Antti Palosaari <crope@xxxxxx>
Reviewed-by: Adam Baker <linux@xxxxxxxxxxxxxxxx>
---
drivers/media/dvb-frontends/si2168.c | 135 +++++++++++++++++-------------
drivers/media/dvb-frontends/si2168_priv.h | 1 -
2 files changed, 79 insertions(+), 57 deletions(-)
diff --git a/drivers/media/dvb-frontends/si2168.c b/drivers/media/dvb-frontends/si2168.c
index b68ab34..d6a4cb0 100644
--- a/drivers/media/dvb-frontends/si2168.c
+++ b/drivers/media/dvb-frontends/si2168.c
@@ -18,23 +18,53 @@
static const struct dvb_frontend_ops si2168_ops;
+/* Own I2C adapter locking is needed because of I2C gate logic. */
+static int si2168_i2c_master_send_unlocked(const struct i2c_client *client,
+ const char *buf, int count)
+{
+ int ret;
+ struct i2c_msg msg = {
+ .addr = client->addr,
+ .flags = 0,
+ .len = count,
+ .buf = (char *)buf,
+ };
+
+ ret = __i2c_transfer(client->adapter, &msg, 1);
+ return (ret == 1) ? count : ret;
+}
+
+static int si2168_i2c_master_recv_unlocked(const struct i2c_client *client,
+ char *buf, int count)
+{
+ int ret;
+ struct i2c_msg msg = {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .len = count,
+ .buf = buf,
+ };
+
+ ret = __i2c_transfer(client->adapter, &msg, 1);
+ return (ret == 1) ? count : ret;
+}
+
/* execute firmware command */
-static int si2168_cmd_execute(struct i2c_client *client, struct si2168_cmd *cmd)
+static int si2168_cmd_execute_unlocked(struct i2c_client *client,
+ struct si2168_cmd *cmd)
{
- struct si2168_dev *dev = i2c_get_clientdata(client);
int ret;
unsigned long timeout;
- mutex_lock(&dev->i2c_mutex);
-
if (cmd->wlen) {
/* write cmd and args for firmware */
- ret = i2c_master_send(client, cmd->args, cmd->wlen);
+ ret = si2168_i2c_master_send_unlocked(client, cmd->args,
+ cmd->wlen);
if (ret < 0) {
- goto err_mutex_unlock;
+ goto err;
} else if (ret != cmd->wlen) {
ret = -EREMOTEIO;
- goto err_mutex_unlock;
+ goto err;
}
}
@@ -43,12 +73,13 @@ static int si2168_cmd_execute(struct i2c_client *client, struct si2168_cmd *cmd)
#define TIMEOUT 70
timeout = jiffies + msecs_to_jiffies(TIMEOUT);
while (!time_after(jiffies, timeout)) {
- ret = i2c_master_recv(client, cmd->args, cmd->rlen);
+ ret = si2168_i2c_master_recv_unlocked(client, cmd->args,
+ cmd->rlen);
if (ret < 0) {
- goto err_mutex_unlock;
+ goto err;
} else if (ret != cmd->rlen) {
ret = -EREMOTEIO;
- goto err_mutex_unlock;
+ goto err;
}
/* firmware ready? */
@@ -63,24 +94,32 @@ static int si2168_cmd_execute(struct i2c_client *client, struct si2168_cmd *cmd)
/* error bit set? */
if ((cmd->args[0] >> 6) & 0x01) {
ret = -EREMOTEIO;
- goto err_mutex_unlock;
+ goto err;
}
if (!((cmd->args[0] >> 7) & 0x01)) {
ret = -ETIMEDOUT;
- goto err_mutex_unlock;
+ goto err;
}
}
- mutex_unlock(&dev->i2c_mutex);
return 0;
-
-err_mutex_unlock:
- mutex_unlock(&dev->i2c_mutex);
+err:
dev_dbg(&client->dev, "failed=%d\n", ret);
return ret;
}
+static int si2168_cmd_execute(struct i2c_client *client, struct si2168_cmd *cmd)
+{
+ int ret;
+
+ i2c_lock_adapter(client->adapter);
+ ret = si2168_cmd_execute_unlocked(client, cmd);
+ i2c_unlock_adapter(client->adapter);
+
+ return ret;
+}
+
static int si2168_read_status(struct dvb_frontend *fe, fe_status_t *status)
{
struct i2c_client *client = fe->demodulator_priv;
@@ -569,60 +608,46 @@ static int si2168_get_tune_settings(struct dvb_frontend *fe,
/*
* I2C gate logic
- * We must use unlocked i2c_transfer() here because I2C lock is already taken
- * by tuner driver.
+ * We must use unlocked I2C I/O because I2C adapter lock is already taken
+ * by the caller (usually tuner driver).
*/
static int si2168_select(struct i2c_adapter *adap, void *mux_priv, u32 chan)
{
struct i2c_client *client = mux_priv;
- struct si2168_dev *dev = i2c_get_clientdata(client);
int ret;
- struct i2c_msg gate_open_msg = {
- .addr = client->addr,
- .flags = 0,
- .len = 3,
- .buf = "\xc0\x0d\x01",
- };
-
- mutex_lock(&dev->i2c_mutex);
+ struct si2168_cmd cmd;
- /* open tuner I2C gate */
- ret = __i2c_transfer(client->adapter, &gate_open_msg, 1);
- if (ret != 1) {
- dev_warn(&client->dev, "i2c write failed=%d\n", ret);
- if (ret >= 0)
- ret = -EREMOTEIO;
- } else {
- ret = 0;
- }
+ /* open I2C gate */
+ memcpy(cmd.args, "\xc0\x0d\x01", 3);
+ cmd.wlen = 3;
+ cmd.rlen = 0;
+ ret = si2168_cmd_execute_unlocked(client, &cmd);
+ if (ret)
+ goto err;
+ return 0;
+err:
+ dev_dbg(&client->dev, "failed=%d\n", ret);
return ret;
}
static int si2168_deselect(struct i2c_adapter *adap, void *mux_priv, u32 chan)
{
struct i2c_client *client = mux_priv;
- struct si2168_dev *dev = i2c_get_clientdata(client);
int ret;
- struct i2c_msg gate_close_msg = {
- .addr = client->addr,
- .flags = 0,
- .len = 3,
- .buf = "\xc0\x0d\x00",
- };
-
- /* close tuner I2C gate */
- ret = __i2c_transfer(client->adapter, &gate_close_msg, 1);
- if (ret != 1) {
- dev_warn(&client->dev, "i2c write failed=%d\n", ret);
- if (ret >= 0)
- ret = -EREMOTEIO;
- } else {
- ret = 0;
- }
+ struct si2168_cmd cmd;
- mutex_unlock(&dev->i2c_mutex);
+ /* close I2C gate */
+ memcpy(cmd.args, "\xc0\x0d\x00", 3);
+ cmd.wlen = 3;
+ cmd.rlen = 0;
+ ret = si2168_cmd_execute_unlocked(client, &cmd);
+ if (ret)
+ goto err;
+ return 0;
+err:
+ dev_dbg(&client->dev, "failed=%d\n", ret);
return ret;
}
@@ -679,8 +704,6 @@ static int si2168_probe(struct i2c_client *client,
goto err;
}
- mutex_init(&dev->i2c_mutex);
-
/* create mux i2c adapter for tuner */
dev->adapter = i2c_add_mux_adapter(client->adapter, &client->dev,
client, 0, 0, 0, si2168_select, si2168_deselect);
diff --git a/drivers/media/dvb-frontends/si2168_priv.h b/drivers/media/dvb-frontends/si2168_priv.h
index d2589e3..90b6b6e 100644
--- a/drivers/media/dvb-frontends/si2168_priv.h
+++ b/drivers/media/dvb-frontends/si2168_priv.h
@@ -30,7 +30,6 @@
/* state struct */
struct si2168_dev {
struct i2c_adapter *adapter;
- struct mutex i2c_mutex;
struct dvb_frontend fe;
fe_delivery_system_t delivery_system;
fe_status_t fe_status;
--
http://palosaari.fi/
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