imx6solo i2c bus busy issue

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imx6solo i2c bus busy issue

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Contributor II

system: linux 4.1.15

soc:imx6s

1.some time i2c work error ,log is

i2c i2c-1: master_xfer[0] W, addr=0x18, len=2
[ 1.625649] i2c i2c-1: <i2c_imx_xfer>
[ 1.625657] i2c i2c-1: <i2c_imx_start>
[ 1.625715] <i2c_imx_bus_busy>
[ 1.625722] <i2c_imx_bus_busy> I2C bus is busy temp 83
[ 1.625733] i2c i2c-1: <i2c_imx_xfer> exit with: error: -11

2.if i2c bus busy happen,hi was always busy and  i2c sdl sck no wave form。

3. device tree config

imx6qdl.dtsi

i2c2 = &i2c3;

i2c3: i2c@021a8000 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "fsl,imx6q-i2c", "fsl,imx21-i2c";
reg = <0x021a8000 0x4000>;
interrupts = <0 38 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&clks IMX6QDL_CLK_I2C3>;
status = "disabled";
};

imx6qdl-sabresd.dtsi

&i2c2{
clock-frequency = <100000>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_i2c2>;
status = "okay";

4.the log code is i2c-imx.c

/** Functions for IMX I2C adapter driver ***************************************
*******************************************************************************/

static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
{
unsigned long orig_jiffies = jiffies;
unsigned int temp;

dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);

while (1) {
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);

/* check for arbitration lost */
if (temp & I2SR_IAL) {
temp &= ~I2SR_IAL;
printk("<%s> is busy temp %x\n", __func__,temp);
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
return -EAGAIN;
}

if (for_busy && (temp & I2SR_IBB))
break;
if (!for_busy && !(temp & I2SR_IBB))
break;
if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
dev_dbg(&i2c_imx->adapter.dev,
"<%s> I2C bus is busy\n", __func__);
return -ETIMEDOUT;
}
schedule();
}

return 0;
}

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NXP TechSupport
NXP TechSupport

Hi huang

one can check if i2c lines are not hold by some device with oscilloscope, use

AN4553 Using Open Source Debugging Tools for Linux on i.MX Processors
https://www.nxp.com/docs/en/application-note/AN4553.pdf 

Best regards
igor
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NXP TechSupport
NXP TechSupport

Hi huang

one can check if i2c lines are not hold by some device with oscilloscope, use

AN4553 Using Open Source Debugging Tools for Linux on i.MX Processors
https://www.nxp.com/docs/en/application-note/AN4553.pdf 

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

View solution in original post

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