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-rw-r--r--drivers/i2c/busses/i2c-stm32f7.c20
1 files changed, 19 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index b9b19a2a2ffa..ed977b6f7ab6 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -1696,6 +1696,16 @@ static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap,
time_left = wait_for_completion_timeout(&i2c_dev->complete,
i2c_dev->adap.timeout);
ret = f7_msg->result;
+ if (ret) {
+ /*
+ * It is possible that some unsent data have already been
+ * written into TXDR. To avoid sending old data in a
+ * further transfer, flush TXDR in case of any error
+ */
+ writel_relaxed(STM32F7_I2C_ISR_TXE,
+ i2c_dev->base + STM32F7_I2C_ISR);
+ goto pm_free;
+ }
if (!time_left) {
dev_dbg(i2c_dev->dev, "Access to slave 0x%x timed out\n",
@@ -1744,8 +1754,16 @@ static int stm32f7_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
timeout = wait_for_completion_timeout(&i2c_dev->complete,
i2c_dev->adap.timeout);
ret = f7_msg->result;
- if (ret)
+ if (ret) {
+ /*
+ * It is possible that some unsent data have already been
+ * written into TXDR. To avoid sending old data in a
+ * further transfer, flush TXDR in case of any error
+ */
+ writel_relaxed(STM32F7_I2C_ISR_TXE,
+ i2c_dev->base + STM32F7_I2C_ISR);
goto pm_free;
+ }
if (!timeout) {
dev_dbg(dev, "Access to slave 0x%x timed out\n", f7_msg->addr);