linux-kernel - [PATCH v3 2/3] i2c: imx: Simplify stopped state tracking

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Date:   Thu,  9 Aug 2018 14:32:06 +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>,
        Fabio Estevam <fabio.estevam@....com>,
        Wei Jinhua <wei.jinhua1@....com.cn>,
        Phil Reid <preid@...ctromag.com.au>,
        Peter Rosin <peda@...ntia.se>, linux-kernel@...r.kernel.org
Subject: [PATCH v3 2/3] 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 | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index f7bd6c21da27..8fb61691e226 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -421,10 +421,14 @@ 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__);
@@ -538,7 +542,6 @@ 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;
@@ -567,10 +570,8 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
 		udelay(i2c_imx->disable_delay);
 	}
 
-	if (!i2c_imx->stopped) {
+	if (!i2c_imx->stopped)
 		i2c_imx_bus_busy(i2c_imx, 0);
-		i2c_imx->stopped = 1;
-	}
 
 	/* Disable I2C controller */
 	temp = i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
@@ -724,7 +725,6 @@ 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:
@@ -849,7 +849,6 @@ 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:
-- 
2.18.0