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Commit d2b72f64 authored by Antti Palosaari's avatar Antti Palosaari Committed by Mauro Carvalho Chehab
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[media] si2168: Implement own I2C adapter locking 



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: default avatarAdam Baker <linux@baker-net.org.uk>
Signed-off-by: default avatarAntti Palosaari <crope@iki.fi>
Reviewed-by: default avatarAdam Baker <linux@baker-net.org.uk>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@osg.samsung.com>
parent c1c3c85d

drivers/media/dvb-frontends/si2168.c

+79 −56
Original line number Diff line number Diff line
@@ -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);

drivers/media/dvb-frontends/si2168_priv.h

+0 −1
Original line number Diff line number Diff line
@@ -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;