diff options
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-xlp9xx.c | 41 | ||||
| -rw-r--r-- | drivers/i2c/i2c-core-smbus.c | 28 |
2 files changed, 48 insertions, 21 deletions
diff --git a/drivers/i2c/busses/i2c-xlp9xx.c b/drivers/i2c/busses/i2c-xlp9xx.c index 1f41a4f89c08..8a873975cf12 100644 --- a/drivers/i2c/busses/i2c-xlp9xx.c +++ b/drivers/i2c/busses/i2c-xlp9xx.c @@ -191,28 +191,43 @@ static void xlp9xx_i2c_drain_rx_fifo(struct xlp9xx_i2c_dev *priv) if (priv->len_recv) { /* read length byte */ rlen = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO); + + /* + * We expect at least 2 interrupts for I2C_M_RECV_LEN + * transactions. The length is updated during the first + * interrupt, and the buffer contents are only copied + * during subsequent interrupts. If in case the interrupts + * get merged we would complete the transaction without + * copying out the bytes from RX fifo. To avoid this now we + * drain the fifo as and when data is available. + * We drained the rlen byte already, decrement total length + * by one. + */ + + len--; if (rlen > I2C_SMBUS_BLOCK_MAX || rlen == 0) { rlen = 0; /*abort transfer */ priv->msg_buf_remaining = 0; priv->msg_len = 0; - } else { - *buf++ = rlen; - if (priv->client_pec) - ++rlen; /* account for error check byte */ - /* update remaining bytes and message length */ - priv->msg_buf_remaining = rlen; - priv->msg_len = rlen + 1; + xlp9xx_i2c_update_rlen(priv); + return; } + + *buf++ = rlen; + if (priv->client_pec) + ++rlen; /* account for error check byte */ + /* update remaining bytes and message length */ + priv->msg_buf_remaining = rlen; + priv->msg_len = rlen + 1; xlp9xx_i2c_update_rlen(priv); priv->len_recv = false; - } else { - len = min(priv->msg_buf_remaining, len); - for (i = 0; i < len; i++, buf++) - *buf = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO); - - priv->msg_buf_remaining -= len; } + len = min(priv->msg_buf_remaining, len); + for (i = 0; i < len; i++, buf++) + *buf = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO); + + priv->msg_buf_remaining -= len; priv->msg_buf = buf; if (priv->msg_buf_remaining) diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c index 51970bae3c4a..9cd66cabb84f 100644 --- a/drivers/i2c/i2c-core-smbus.c +++ b/drivers/i2c/i2c-core-smbus.c @@ -463,7 +463,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, msg[num-1].len++; } - status = i2c_transfer(adapter, msg, num); + status = __i2c_transfer(adapter, msg, num); if (status < 0) goto cleanup; if (status != num) { @@ -524,9 +524,24 @@ cleanup: * This executes an SMBus protocol operation, and returns a negative * errno code else zero on success. */ -s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, - char read_write, u8 command, int protocol, - union i2c_smbus_data *data) +s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, + unsigned short flags, char read_write, + u8 command, int protocol, union i2c_smbus_data *data) +{ + s32 res; + + i2c_lock_bus(adapter, I2C_LOCK_SEGMENT); + res = __i2c_smbus_xfer(adapter, addr, flags, read_write, + command, protocol, data); + i2c_unlock_bus(adapter, I2C_LOCK_SEGMENT); + + return res; +} +EXPORT_SYMBOL(i2c_smbus_xfer); + +s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, + unsigned short flags, char read_write, + u8 command, int protocol, union i2c_smbus_data *data) { unsigned long orig_jiffies; int try; @@ -543,8 +558,6 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB; if (adapter->algo->smbus_xfer) { - i2c_lock_bus(adapter, I2C_LOCK_SEGMENT); - /* Retry automatically on arbitration loss */ orig_jiffies = jiffies; for (res = 0, try = 0; try <= adapter->retries; try++) { @@ -557,7 +570,6 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, orig_jiffies + adapter->timeout)) break; } - i2c_unlock_bus(adapter, I2C_LOCK_SEGMENT); if (res != -EOPNOTSUPP || !adapter->algo->master_xfer) goto trace; @@ -579,7 +591,7 @@ trace: return res; } -EXPORT_SYMBOL(i2c_smbus_xfer); +EXPORT_SYMBOL(__i2c_smbus_xfer); /** * i2c_smbus_read_i2c_block_data_or_emulated - read block or emulate |
