From e349d7d08e7044caf37a36409305edbd5af013c7 Mon Sep 17 00:00:00 2001 From: George Cherian Date: Tue, 27 Feb 2018 13:26:19 +0000 Subject: [PATCH] i2c: xlp9xx: Handle NACK on DATA properly In case we receive NACK on DATA we shouldn't be resetting the controller, rather we should issue STOP command. This will terminate the current transaction and -EIO is returned. While at that handle the SMBus Quick Command properly. We shouldn't be setting the XLP9XX_I2C_CMD_READ/WRITE for such transactions. Signed-off-by: George Cherian Reviewed-by: Jan Glauber Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-xlp9xx.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/i2c/busses/i2c-xlp9xx.c b/drivers/i2c/busses/i2c-xlp9xx.c index 42dd1fa0b644..eb8913eba0c5 100644 --- a/drivers/i2c/busses/i2c-xlp9xx.c +++ b/drivers/i2c/busses/i2c-xlp9xx.c @@ -352,7 +352,9 @@ static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev *priv, struct i2c_msg *msg, /* set cmd reg */ cmd = XLP9XX_I2C_CMD_START; - cmd |= (priv->msg_read ? XLP9XX_I2C_CMD_READ : XLP9XX_I2C_CMD_WRITE); + if (msg->len) + cmd |= (priv->msg_read ? + XLP9XX_I2C_CMD_READ : XLP9XX_I2C_CMD_WRITE); if (last_msg) cmd |= XLP9XX_I2C_CMD_STOP; @@ -361,12 +363,12 @@ static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev *priv, struct i2c_msg *msg, timeleft = msecs_to_jiffies(XLP9XX_I2C_TIMEOUT_MS); timeleft = wait_for_completion_timeout(&priv->msg_complete, timeleft); - if (priv->msg_err) { + if (priv->msg_err & XLP9XX_I2C_INTEN_BUSERR) { dev_dbg(priv->dev, "transfer error %x!\n", priv->msg_err); - if (priv->msg_err & XLP9XX_I2C_INTEN_BUSERR) - xlp9xx_i2c_init(priv); - return (priv->msg_err & XLP9XX_I2C_INTEN_NACKADDR) ? - -ENXIO : -EIO; + xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CMD, XLP9XX_I2C_CMD_STOP); + return -EIO; + } else if (priv->msg_err & XLP9XX_I2C_INTEN_NACKADDR) { + return -ENXIO; } if (timeleft == 0) {