diff options
| author | Marek Vasut <marex@denx.de> | 2021-08-23 23:41:40 +0200 |
|---|---|---|
| committer | Wolfram Sang <wsa@kernel.org> | 2021-09-14 12:22:41 +0200 |
| commit | c119e7d00c916881913011e6f4c6ac349a41e4e2 (patch) | |
| tree | 811e0e6738a4eff03a34e6cabc802ca04e20d7f5 /drivers/i2c | |
| parent | 6880fa6c56601bb8ed59df6c30fd390cc5f6dd8f (diff) | |
| download | lwn-c119e7d00c916881913011e6f4c6ac349a41e4e2.tar.gz lwn-c119e7d00c916881913011e6f4c6ac349a41e4e2.zip | |
i2c: xiic: Fix broken locking on tx_msg
The tx_msg is set from multiple places, sometimes without locking,
which fall apart on any SMP system. Only ever access tx_msg inside
the driver mutex.
Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-xiic.c | 26 |
1 files changed, 16 insertions, 10 deletions
diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c index bb93db98404e..50320dd32eea 100644 --- a/drivers/i2c/busses/i2c-xiic.c +++ b/drivers/i2c/busses/i2c-xiic.c @@ -170,7 +170,7 @@ struct xiic_i2c { #define xiic_tx_space(i2c) ((i2c)->tx_msg->len - (i2c)->tx_pos) #define xiic_rx_space(i2c) ((i2c)->rx_msg->len - (i2c)->rx_pos) -static int xiic_start_xfer(struct xiic_i2c *i2c); +static int xiic_start_xfer(struct xiic_i2c *i2c, struct i2c_msg *msgs, int num); static void __xiic_start_xfer(struct xiic_i2c *i2c); /* @@ -684,15 +684,25 @@ static void __xiic_start_xfer(struct xiic_i2c *i2c) } -static int xiic_start_xfer(struct xiic_i2c *i2c) +static int xiic_start_xfer(struct xiic_i2c *i2c, struct i2c_msg *msgs, int num) { int ret; + mutex_lock(&i2c->lock); + ret = xiic_busy(i2c); + if (ret) + goto out; + + i2c->tx_msg = msgs; + i2c->rx_msg = NULL; + i2c->nmsgs = num; + ret = xiic_reinit(i2c); if (!ret) __xiic_start_xfer(i2c); +out: mutex_unlock(&i2c->lock); return ret; @@ -710,14 +720,7 @@ static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) if (err < 0) return err; - err = xiic_busy(i2c); - if (err) - goto out; - - i2c->tx_msg = msgs; - i2c->nmsgs = num; - - err = xiic_start_xfer(i2c); + err = xiic_start_xfer(i2c, msgs, num); if (err < 0) { dev_err(adap->dev.parent, "Error xiic_start_xfer\n"); goto out; @@ -725,9 +728,11 @@ static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) || (i2c->state == STATE_DONE), HZ)) { + mutex_lock(&i2c->lock); err = (i2c->state == STATE_DONE) ? num : -EIO; goto out; } else { + mutex_lock(&i2c->lock); i2c->tx_msg = NULL; i2c->rx_msg = NULL; i2c->nmsgs = 0; @@ -735,6 +740,7 @@ static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) goto out; } out: + mutex_unlock(&i2c->lock); pm_runtime_mark_last_busy(i2c->dev); pm_runtime_put_autosuspend(i2c->dev); return err; |