i2c: imx: Don't generate STOP condition if arbitration has been lost (61e6fe59) · Commits · 戴 / test

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>

drivers/i2c/busses/i2c-imx.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -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;
		@@ -778,8 +780,11 @@ 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);
		if (!i2c_imx->stopped)
		i2c_imx_bus_busy(i2c_imx, 0, false);
		} else {
		/*
		@@ -905,8 +910,11 @@ 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);
		if (!i2c_imx->stopped)
		i2c_imx_bus_busy(i2c_imx, 0, atomic);
		} else {
		/*

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