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| author | Christian Eggers <ceggers@arri.de> | 2020-10-09 13:03:20 +0200 |
|---|---|---|
| committer | Wolfram Sang <wsa@kernel.org> | 2020-12-02 21:28:20 +0100 |
| commit | 61e6fe59ede155881a622f5901551b1cc8748f6a (patch) | |
| tree | 862c85c425fc9500c197b9b5b3f39fabead5aab5 /drivers/i2c | |
| parent | i2c: imx: Check for I2SR_IAL after every byte (diff) | |
| download | linux-61e6fe59ede155881a622f5901551b1cc8748f6a.tar.xz linux-61e6fe59ede155881a622f5901551b1cc8748f6a.zip | |
i2c: imx: Don't generate STOP condition if arbitration has been lost
If arbitration is lost, the master automatically changes to slave mode.
I2SR_IBB may or may not be reset by hardware. Raising a STOP condition
by resetting I2CR_MSTA has no effect and will not clear I2SR_IBB.
So calling i2c_imx_bus_busy() is not required and would busy-wait until
timeout.
Signed-off-by: Christian Eggers <ceggers@arri.de>
Tested (not extensively) on Vybrid VF500 (Toradex VF50):
Tested-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Cc: stable@vger.kernel.org # Requires trivial backporting, simple remove
# the 3rd argument from the calls to
# i2c_imx_bus_busy().
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-imx.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index a2abae124342..e6f8d6e45a15 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -615,6 +615,8 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx, bool atomic) /* Stop I2C transaction */ dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__); temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + if (!(temp & I2CR_MSTA)) + i2c_imx->stopped = 1; temp &= ~(I2CR_MSTA | I2CR_MTX); if (i2c_imx->dma) temp &= ~I2CR_DMAEN; @@ -778,9 +780,12 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx, */ dev_dbg(dev, "<%s> clear MSTA\n", __func__); temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + if (!(temp & I2CR_MSTA)) + i2c_imx->stopped = 1; temp &= ~(I2CR_MSTA | I2CR_MTX); imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); - i2c_imx_bus_busy(i2c_imx, 0, false); + if (!i2c_imx->stopped) + i2c_imx_bus_busy(i2c_imx, 0, false); } else { /* * For i2c master receiver repeat restart operation like: @@ -905,9 +910,12 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, dev_dbg(&i2c_imx->adapter.dev, "<%s> clear MSTA\n", __func__); temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + if (!(temp & I2CR_MSTA)) + i2c_imx->stopped = 1; temp &= ~(I2CR_MSTA | I2CR_MTX); imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); - i2c_imx_bus_busy(i2c_imx, 0, atomic); + if (!i2c_imx->stopped) + i2c_imx_bus_busy(i2c_imx, 0, atomic); } else { /* * For i2c master receiver repeat restart operation like: |