i2c: uniphier: issue STOP only for last message or I2C_M_STOP

This driver currently emits a STOP if the next message is not
I2C_MD_RD.  It should not do it because it disturbs the I2C_RDWR
ioctl, where read/write transactions are combined without STOP
between.

Issue STOP only when the message is the last one _or_ flagged with
I2C_M_STOP.

Fixes: dd6fd4a32793 ("i2c: uniphier: add UniPhier FIFO-less I2C driver")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

1 files changed, 2 insertions, 5 deletions

diff --git a/drivers/i2c/busses/i2c-uniphier.c b/drivers/i2c/busses/i2c-uniphier.c
index bb181b088291..454f914ae66d 100644
--- a/drivers/i2c/busses/i2c-uniphier.c
+++ b/drivers/i2c/busses/i2c-uniphier.c
@@ -248,11 +248,8 @@ static int uniphier_i2c_master_xfer(struct i2c_adapter *adap,
                 return ret;
 
         for (msg = msgs; msg < emsg; msg++) {
-                /* If next message is read, skip the stop condition */
-                bool stop = !(msg + 1 < emsg && msg[1].flags & I2C_M_RD);
-                /* but, force it if I2C_M_STOP is set */
-                if (msg->flags & I2C_M_STOP)
-                        stop = true;
+                /* Emit STOP if it is the last message or I2C_M_STOP is set. */
+                bool stop = (msg + 1 == emsg) || (msg->flags & I2C_M_STOP);
 
                 ret = uniphier_i2c_master_xfer_one(adap, msg, stop);
                 if (ret)