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Commit d6dbd939 authored by Andy Walls's avatar Andy Walls Committed by Mauro Carvalho Chehab
Browse files

[media] lirc_zilog: Add locking of the i2c_clients when in use 



Lock the i2c_client pointers and prevent i2c_client removal when
lirc_zilog is perfoming a series of operations that require valid
i2c_client pointers.

Signed-off-by: default avatarAndy Walls <awalls@md.metrocast.net>
Signed-off-by: default avatarJarod Wilson <jarod@redhat.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 5bd6b046

drivers/staging/lirc/lirc_zilog.c

+37 −4
Original line number Diff line number Diff line
@@ -70,7 +70,7 @@ struct IR_rx { 
	struct IR *ir;



	/* RX device */

	/* FIXME mutex lock access to this pointer */

	struct mutex client_lock;

	struct i2c_client *c;



	/* RX polling thread data */
@@ -86,7 +86,7 @@ struct IR_tx { 
	struct IR *ir;



	/* TX device */

	/* FIXME mutex lock access to this pointer */

	struct mutex client_lock;

	struct i2c_client *c;



	/* TX additional actions needed */
@@ -341,6 +341,14 @@ static int add_to_buf(struct IR *ir) 
	if (rx == NULL)

		return -ENXIO;



	/* Ensure our rx->c i2c_client remains valid for the duration */

	mutex_lock(&rx->client_lock);

	if (rx->c == NULL) {

		mutex_unlock(&rx->client_lock);

		put_ir_rx(rx, false);

		return -ENXIO;

	}



	tx = get_ir_tx(ir);



	/*
@@ -442,6 +450,7 @@ static int add_to_buf(struct IR *ir) 
		ret = 0;

	} while (!lirc_buffer_full(rbuf));



	mutex_unlock(&rx->client_lock);

	if (tx != NULL)

		put_ir_tx(tx, false);

	put_ir_rx(rx, false);
@@ -1089,6 +1098,14 @@ static ssize_t write(struct file *filep, const char *buf, size_t n, 
	if (tx == NULL)

		return -ENXIO;



	/* Ensure our tx->c i2c_client remains valid for the duration */

	mutex_lock(&tx->client_lock);

	if (tx->c == NULL) {

		mutex_unlock(&tx->client_lock);

		put_ir_tx(tx, false);

		return -ENXIO;

	}



	/* Lock i2c bus for the duration */

	mutex_lock(&ir->ir_lock);
@@ -1099,6 +1116,7 @@ static ssize_t write(struct file *filep, const char *buf, size_t n, 


		if (copy_from_user(&command, buf + i, sizeof(command))) {

			mutex_unlock(&ir->ir_lock);

			mutex_unlock(&tx->client_lock);

			put_ir_tx(tx, false);

			return -EFAULT;

		}
@@ -1109,6 +1127,7 @@ static ssize_t write(struct file *filep, const char *buf, size_t n, 
			ret = fw_load(tx);

			if (ret != 0) {

				mutex_unlock(&ir->ir_lock);

				mutex_unlock(&tx->client_lock);

				put_ir_tx(tx, false);

				if (ret != -ENOMEM)

					ret = -EIO;
@@ -1126,6 +1145,7 @@ static ssize_t write(struct file *filep, const char *buf, size_t n, 
					    (unsigned)command & 0xFFFF);

			if (ret == -EPROTO) {

				mutex_unlock(&ir->ir_lock);

				mutex_unlock(&tx->client_lock);

				put_ir_tx(tx, false);

				return ret;

			}
@@ -1144,6 +1164,7 @@ static ssize_t write(struct file *filep, const char *buf, size_t n, 
				zilog_error("unable to send to the IR chip "

					    "after 3 resets, giving up\n");

				mutex_unlock(&ir->ir_lock);

				mutex_unlock(&tx->client_lock);

				put_ir_tx(tx, false);

				return ret;

			}
@@ -1158,6 +1179,8 @@ static ssize_t write(struct file *filep, const char *buf, size_t n, 
	/* Release i2c bus */

	mutex_unlock(&ir->ir_lock);



	mutex_unlock(&tx->client_lock);



	/* Give back our struct IR_tx reference */

	put_ir_tx(tx, false);
@@ -1365,13 +1388,21 @@ static int ir_remove(struct i2c_client *client) 
{

	if (strncmp("ir_tx_z8", client->name, 8) == 0) {

		struct IR_tx *tx = i2c_get_clientdata(client);

		if (tx != NULL)

		if (tx != NULL) {

			mutex_lock(&tx->client_lock);

			tx->c = NULL;

			mutex_unlock(&tx->client_lock);

			put_ir_tx(tx, false);

		}

	} else if (strncmp("ir_rx_z8", client->name, 8) == 0) {

		struct IR_rx *rx = i2c_get_clientdata(client);

		if (rx != NULL)

		if (rx != NULL) {

			mutex_lock(&rx->client_lock);

			rx->c = NULL;

			mutex_unlock(&rx->client_lock);

			put_ir_rx(rx, false);

		}

	}

	return 0;

}
@@ -1472,6 +1503,7 @@ static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id) 
		ir->tx = tx;



		ir->l.features |= LIRC_CAN_SEND_PULSE;

		mutex_init(&tx->client_lock);

		tx->c = client;

		tx->need_boot = 1;

		tx->post_tx_ready_poll =
@@ -1514,6 +1546,7 @@ static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id) 
		ir->rx = rx;



		ir->l.features |= LIRC_CAN_REC_LIRCCODE;

		mutex_init(&rx->client_lock);

		rx->c = client;

		rx->hdpvr_data_fmt =

			       (id->driver_data & ID_FLAG_HDPVR) ? true : false;