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

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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: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Andy Walls 2011-02-17 20:50:38 -03:00 committed by Mauro Carvalho Chehab
parent 5bd6b0464b
commit d6dbd939b9
1 changed files with 37 additions and 4 deletions
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41
drivers/staging/lirc/lirc_zilog.c
View file

@ -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);
@ -1365,12 +1388,20 @@ 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;