linux-kernel - [PATCH 3/4] i2c: imx: Simplify stopped state tracking

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Date:   Wed, 23 May 2018 11:56:22 +0200
From:   Esben Haabendal <esben.haabendal@...il.com>
To:     linux-i2c@...r.kernel.org
Cc:     Esben Haabendal <eha@...f.com>,
        Wolfram Sang <wsa+renesas@...g-engineering.com>,
        Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>,
        Lucas Stach <l.stach@...gutronix.de>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Michail Georgios Etairidis <m.etairidis@...k-ipc.com>,
        Wei Jinhua <wei.jinhua1@....com.cn>,
        Phil Reid <preid@...ctromag.com.au>,
        linux-kernel@...r.kernel.org
Subject: [PATCH 3/4] i2c: imx: Simplify stopped state tracking

From: Esben Haabendal <eha@...f.com>

Always update the stopped state when busy status have been checked.
This is identical to what was done before, with the exception of error
handling.
Without this change, some errors cause the stopped state to be left in
incorrect state in i2c_imx_stop(), i2c_imx_dma_read(), i2c_imx_read() and
i2c_imx_xfer().

Signed-off-by: Esben Haabendal <eha@...f.com>
---
 drivers/i2c/busses/i2c-imx.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 742b548437af..f9c99b123188 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -430,10 +430,14 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
 			return -EAGAIN;
 		}
 
-		if (for_busy && (temp & I2SR_IBB))
+		if (for_busy && (temp & I2SR_IBB)) {
+			i2c_imx->stopped = 0;
 			break;
-		if (!for_busy && !(temp & I2SR_IBB))
+		}
+		if (!for_busy && !(temp & I2SR_IBB)) {
+			i2c_imx->stopped = 1;
 			break;
+		}
 		if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
 			dev_dbg(&i2c_imx->adapter.dev,
 				"<%s> I2C bus is busy\n", __func__);
@@ -547,7 +551,6 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
 	result = i2c_imx_bus_busy(i2c_imx, 1);
 	if (result)
 		return result;
-	i2c_imx->stopped = 0;
 
 	temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
 	temp &= ~I2CR_DMAEN;
@@ -578,7 +581,6 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
 
 	if (!i2c_imx->stopped) {
 		i2c_imx_bus_busy(i2c_imx, 0);
-		i2c_imx->stopped = 1;
 	}
 
 	/* Disable I2C controller */
@@ -733,7 +735,6 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
 		temp &= ~(I2CR_MSTA | I2CR_MTX);
 		imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 		i2c_imx_bus_busy(i2c_imx, 0);
-		i2c_imx->stopped = 1;
 	} else {
 		/*
 		 * For i2c master receiver repeat restart operation like:
@@ -861,7 +862,6 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo
 				temp &= ~(I2CR_MSTA | I2CR_MTX);
 				imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 				i2c_imx_bus_busy(i2c_imx, 0);
-				i2c_imx->stopped = 1;
 			} else {
 				/*
 				 * For i2c master receiver repeat restart operation like:
-- 
2.17.0