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| author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2018-08-31 23:30:47 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-10-10 08:54:21 +0200 |
| commit | 82fc9c6b7b9a355b3e794386c7630a076d762072 (patch) | |
| tree | 943076471a3c195cc199a6a1510d4b323d5b897e /drivers | |
| parent | da26e5729c04de59b41da0e245cae3742bfaaefb (diff) | |
| download | linux-82fc9c6b7b9a355b3e794386c7630a076d762072.tar.gz linux-82fc9c6b7b9a355b3e794386c7630a076d762072.tar.bz2 linux-82fc9c6b7b9a355b3e794386c7630a076d762072.zip | |
i2c: uniphier: issue STOP only for last message or I2C_M_STOP
[ Upstream commit 38f5d8d8cbb2ffa2b54315118185332329ec891c ]
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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/i2c/busses/i2c-uniphier.c | 7 |
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) |