[PATCH 1/3] i2c: owl: Clear NACK and BUS error bits

[Manivannan Sadhasivam]

On Fri, Oct 09, 2020 at 12:44:39AM +0300, Cristian Ciocaltea wrote:
> When the NACK and BUS error bits are set by the hardware, the driver is
> responsible for clearing them by writing "1" into the corresponding
> status registers.
> 
> Hence perform the necessary operations in owl_i2c_interrupt().
> 
> Fixes: d211e62af466 ("i2c: Add Actions Semiconductor Owl family S900 I2C driver")
> Reported-by: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>
> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea at gmail.com>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>

Thanks,
Mani

> ---
>  drivers/i2c/busses/i2c-owl.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/i2c/busses/i2c-owl.c b/drivers/i2c/busses/i2c-owl.c
> index 672f1f239bd6..a163b8f308c1 100644
> --- a/drivers/i2c/busses/i2c-owl.c
> +++ b/drivers/i2c/busses/i2c-owl.c
> @@ -176,6 +176,9 @@ static irqreturn_t owl_i2c_interrupt(int irq, void *_dev)
>  	fifostat = readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT);
>  	if (fifostat & OWL_I2C_FIFOSTAT_RNB) {
>  		i2c_dev->err = -ENXIO;
> +		/* Clear NACK error bit by writing "1" */
> +		owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOSTAT,
> +				   OWL_I2C_FIFOSTAT_RNB, true);
>  		goto stop;
>  	}
>  
> @@ -183,6 +186,9 @@ static irqreturn_t owl_i2c_interrupt(int irq, void *_dev)
>  	stat = readl(i2c_dev->base + OWL_I2C_REG_STAT);
>  	if (stat & OWL_I2C_STAT_BEB) {
>  		i2c_dev->err = -EIO;
> +		/* Clear BUS error bit by writing "1" */
> +		owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_STAT,
> +				   OWL_I2C_STAT_BEB, true);
>  		goto stop;
>  	}
>  
> -- 
> 2.28.0
>