In `i2c_dw_process_transfer()`, if STOP_DET flag is set while read or
write is in progress, the transfer should be aborted. If this flag is
handled the same interrupt as TX_EMPTY flag, the driver first handles
TX_EMPTY flag and transmits the following messages, and only afterwards
checks STOP_DET flag.

Also, if STOP_DET flag is set, interrupts are not masked, so if TX_EMPTY
interrupts arrives later, the driver will also send further messages.

To abort transmitting data after spurious STOP, check STOP_DET flag
before TX_EMPTY flag, and if STOP_DET flag is set while transfer is in
progress, disable interrupts as it is done in case of TX_ABRT flag set.

Signed-off-by: Dmitry Guzman <[email protected]>
---
 drivers/i2c/busses/i2c-designware-master.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-master.c 
b/drivers/i2c/busses/i2c-designware-master.c
index 
76f28e1696bdc81326cf149dfe88c52dd2f0731f..936b9150754e85a1bac2d17a0fa65f6963e4ef3e
 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -651,17 +651,19 @@ static void i2c_dw_process_transfer(struct dw_i2c_dev 
*dev, unsigned int stat)
        if (stat & DW_IC_INTR_RX_FULL)
                i2c_dw_read(dev);
 
-       if (stat & DW_IC_INTR_TX_EMPTY)
-               i2c_dw_xfer_msg(dev);
-
        /* Abort if we detect a STOP in the middle of a read or a write */
        if ((stat & DW_IC_INTR_STOP_DET) &&
            (dev->status & (STATUS_READ_IN_PROGRESS | 
STATUS_WRITE_IN_PROGRESS))) {
                dev_err(dev->dev, "spurious STOP detected\n");
                dev->rx_outstanding = 0;
                dev->msg_err = -EIO;
+               __i2c_dw_write_intr_mask(dev, 0);
+               goto tx_aborted;
        }
 
+       if (stat & DW_IC_INTR_TX_EMPTY)
+               i2c_dw_xfer_msg(dev);
+
        /*
         * No need to modify or disable the interrupt mask here.
         * i2c_dw_xfer_msg() will take care of it according to

-- 
2.43.0


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