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charset="utf-8" From: Carlos Song Reset I2C controller in probe stage to avoid unexpected LPI2C controller state left from previous stages and hang system boot. Per the LPI2C reference manual, section 7.1.4 "Controller Control (MCR)", the RST bit (bit 1) description states: "The reset takes effect immediately and remains asserted until negated by software. There is no minimum delay required before clearing the software reset." Therefore, it is safe to write 0 to MCR immediately after asserting the RST bit without any additional delay. Signed-off-by: Carlos Song --- drivers/i2c/busses/i2c-imx-lpi2c.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-im= x-lpi2c.c index bf8c1ce1c7ff..96f6dc23232e 100644 --- a/drivers/i2c/busses/i2c-imx-lpi2c.c +++ b/drivers/i2c/busses/i2c-imx-lpi2c.c @@ -1499,11 +1499,6 @@ static int lpi2c_imx_probe(struct platform_device *p= dev) if (ret) lpi2c_imx->bitrate =3D I2C_MAX_STANDARD_MODE_FREQ; =20 - ret =3D devm_request_irq(&pdev->dev, lpi2c_imx->irq, lpi2c_imx_isr, IRQF_= NO_SUSPEND, - pdev->name, lpi2c_imx); - if (ret) - return dev_err_probe(&pdev->dev, ret, "can't claim irq %d\n", lpi2c_imx-= >irq); - i2c_set_adapdata(&lpi2c_imx->adapter, lpi2c_imx); platform_set_drvdata(pdev, lpi2c_imx); =20 @@ -1535,10 +1530,23 @@ static int lpi2c_imx_probe(struct platform_device *= pdev) pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); =20 + /* + * Reset all internal controller logic and registers to avoid effects of = previous status + * The reset takes effect immediately and there is no minimum delay requi= red before + * clearing the software reset. + */ + writel(MCR_RST, lpi2c_imx->base + LPI2C_MCR); + writel(0, lpi2c_imx->base + LPI2C_MCR); + temp =3D readl(lpi2c_imx->base + LPI2C_PARAM); lpi2c_imx->txfifosize =3D 1 << (temp & 0x0f); lpi2c_imx->rxfifosize =3D 1 << ((temp >> 8) & 0x0f); =20 + ret =3D devm_request_irq(&pdev->dev, lpi2c_imx->irq, lpi2c_imx_isr, IRQF_= NO_SUSPEND, + pdev->name, lpi2c_imx); + if (ret) + return dev_err_probe(&pdev->dev, ret, "can't claim irq %d\n", lpi2c_imx-= >irq); + /* Init optional bus recovery function */ ret =3D lpi2c_imx_init_recovery_info(lpi2c_imx, pdev); /* Give it another chance if pinctrl used is not ready yet */ --=20 2.43.0