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authorEsben Haabendal <eha@deif.com>2018-08-16 10:43:13 +0200
committerWolfram Sang <wsa@the-dreams.de>2018-08-20 11:13:16 +0200
commitef456a2de3716e2a38382ff2aa9a9c52962e7e84 (patch)
tree186d7f1f92fb209b3d799c3fb4f8ee769d26b106 /drivers/i2c
parenti2c: imx: Fix race condition in dma read (diff)
downloadlinux-ef456a2de3716e2a38382ff2aa9a9c52962e7e84.tar.xz
linux-ef456a2de3716e2a38382ff2aa9a9c52962e7e84.zip
i2c: imx: Simplify stopped state tracking
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@deif.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-imx.c15
1 files changed, 7 insertions, 8 deletions
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index eb11ac3d6aba..7029542c75fb 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -420,10 +420,14 @@ 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__);
@@ -537,7 +541,6 @@ 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;
@@ -566,10 +569,8 @@ 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,
@@ -725,7 +726,6 @@ 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:
@@ -851,7 +851,6 @@ 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: