From: Dirk Behme <dirk.behme@xxxxxxxxxxxxxx>
This fixes Oops at kernel startup while "scanning" for TLV320AIC23IDx
addresses.
Signed-off-by: Alexander Vasiliev <alexvasiljev@xxxxxxxxx>
Signed-off-by: Brad Griffis <bgriffis@xxxxxx>
Signed-off-by: Dirk Behme <dirk.behme@xxxxxxxxx>
Acked-by: Kevin Hilman <khilman@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-davinci.c | 29 +++++++++++++++++++++++++----
1 files changed, 25 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index c89687a..444a9f2 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -112,6 +112,7 @@ struct davinci_i2c_dev {
u8 *buf;
size_t buf_len;
int irq;
+ int stop;
u8 terminate;
struct i2c_adapter adapter;
};
@@ -249,9 +250,6 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
u16 w;
int r;
- if (msg->len == 0)
- return -EINVAL;
-
if (!pdata)
pdata = &davinci_i2c_platform_data_default;
/* Introduce a delay, required for some boards (e.g Davinci EVM) */
@@ -263,6 +261,7 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
dev->buf = msg->buf;
dev->buf_len = msg->len;
+ dev->stop = stop;
davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len);
@@ -280,6 +279,10 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
flag |= DAVINCI_I2C_MDR_TRX;
if (stop)
flag |= DAVINCI_I2C_MDR_STP;
+ if (msg->len == 0) {
+ flag |= DAVINCI_I2C_MDR_RM;
+ flag &= ~DAVINCI_I2C_MDR_STP;
+ }
/* Enable receive or transmit interrupts */
w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG);
@@ -290,6 +293,16 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w);
dev->terminate = 0;
+
+ /* First byte should be set here, not after interrupt,
+ * because transmit-data-ready interrupt can come before
+ * NACK-interrupt during sending of previous message and
+ * ICDXR may have wrong data */
+ if ((!(msg->flags & I2C_M_RD)) && dev->buf_len) {
+ davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG, *dev->buf++);
+ dev->buf_len--;
+ }
+
/* write the data into mode register */
davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
@@ -371,7 +384,7 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
static u32 i2c_davinci_func(struct i2c_adapter *adap)
{
- return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
static void terminate_read(struct davinci_i2c_dev *dev)
@@ -430,6 +443,14 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
case DAVINCI_I2C_IVR_ARDY:
davinci_i2c_write_reg(dev,
DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_ARDY);
+ if (((dev->buf_len == 0) && (dev->stop != 0)) ||
+ (dev->cmd_err & DAVINCI_I2C_STR_NACK)) {
+ w = davinci_i2c_read_reg(dev,
+ DAVINCI_I2C_MDR_REG);
+ w |= DAVINCI_I2C_MDR_STP;
+ davinci_i2c_write_reg(dev,
+ DAVINCI_I2C_MDR_REG, w);
+ }
complete(&dev->cmd_complete);
break;
--
1.6.6
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