diff options
| -rw-r--r-- | drivers/i2c/busses/i2c-xiic.c | 41 |
1 files changed, 26 insertions, 15 deletions
diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c index bd6e107472b7..4c89aad02451 100644 --- a/drivers/i2c/busses/i2c-xiic.c +++ b/drivers/i2c/busses/i2c-xiic.c @@ -843,23 +843,11 @@ static int xiic_bus_busy(struct xiic_i2c *i2c) return (sr & XIIC_SR_BUS_BUSY_MASK) ? -EBUSY : 0; } -static int xiic_busy(struct xiic_i2c *i2c) +static int xiic_wait_not_busy(struct xiic_i2c *i2c) { int tries = 3; int err; - if (i2c->tx_msg || i2c->rx_msg) - return -EBUSY; - - /* In single master mode bus can only be busy, when in use by this - * driver. If the register indicates bus being busy for some reason we - * should ignore it, since bus will never be released and i2c will be - * stuck forever. - */ - if (i2c->singlemaster) { - return 0; - } - /* for instance if previous transfer was terminated due to TX error * it might be that the bus is on it's way to become available * give it at most 3 ms to wake @@ -1103,13 +1091,36 @@ static int xiic_start_xfer(struct xiic_i2c *i2c, struct i2c_msg *msgs, int num) mutex_lock(&i2c->lock); - ret = xiic_busy(i2c); - if (ret) { + if (i2c->tx_msg || i2c->rx_msg) { dev_err(i2c->adap.dev.parent, "cannot start a transfer while busy\n"); + ret = -EBUSY; goto out; } + /* In single master mode bus can only be busy, when in use by this + * driver. If the register indicates bus being busy for some reason we + * should ignore it, since bus will never be released and i2c will be + * stuck forever. + */ + if (!i2c->singlemaster) { + ret = xiic_wait_not_busy(i2c); + if (ret) { + /* If the bus is stuck in a busy state, such as due to spurious low + * pulses on the bus causing a false start condition to be detected, + * then try to recover by re-initializing the controller and check + * again if the bus is still busy. + */ + dev_warn(i2c->adap.dev.parent, "I2C bus busy timeout, reinitializing\n"); + ret = xiic_reinit(i2c); + if (ret) + goto out; + ret = xiic_wait_not_busy(i2c); + if (ret) + goto out; + } + } + i2c->tx_msg = msgs; i2c->rx_msg = NULL; i2c->nmsgs = num; |