From 38f5d8d8cbb2ffa2b54315118185332329ec891c Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <yamada.masahiro@socionext.com>
Date: Fri, 31 Aug 2018 23:30:47 +0900
Subject: [PATCH] i2c: uniphier: issue STOP only for last message or I2C_M_STOP
Git-commit: 38f5d8d8cbb2ffa2b54315118185332329ec891c
Patch-mainline: v4.19-rc3
References: bsc#1051510
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/i2c/busses/i2c-uniphier.c | 7 ++-----
1 file 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)
--
2.18.0