From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:44044 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726672AbeJIB4O (ORCPT ); Mon, 8 Oct 2018 21:56:14 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Masahiro Yamada , Wolfram Sang , Sasha Levin Subject: [PATCH 4.14 28/94] i2c: uniphier: issue STOP only for last message or I2C_M_STOP Date: Mon, 8 Oct 2018 20:31:09 +0200 Message-Id: <20181008175606.355964527@linuxfoundation.org> In-Reply-To: <20181008175605.067676667@linuxfoundation.org> References: <20181008175605.067676667@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Masahiro Yamada [ 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 Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/busses/i2c-uniphier.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) --- a/drivers/i2c/busses/i2c-uniphier.c +++ b/drivers/i2c/busses/i2c-uniphier.c @@ -248,11 +248,8 @@ static int uniphier_i2c_master_xfer(stru 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)