Re: [PATCH 4/5] i2c: designware: Add debug print for SDA hold time value

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On Tue, 2018-05-29 at 14:27 +0300, Jarkko Nikula wrote:
> SDA hold time is an important timing parameter and often reason for
> arbitration lost errors if not set to a correct value. Add a debug
> print
> for it in order to see what value gets programmed to a HW.
> 
> Signed-off-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
> ---
>  drivers/i2c/busses/i2c-designware-common.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/i2c/busses/i2c-designware-common.c
> b/drivers/i2c/busses/i2c-designware-common.c
> index 4f951486f74a..cb55d7e3af8e 100644
> --- a/drivers/i2c/busses/i2c-designware-common.c
> +++ b/drivers/i2c/busses/i2c-designware-common.c
> @@ -207,6 +207,10 @@ void i2c_dw_set_sda_hold(struct dw_i2c_dev *dev)
>  		 */
>  		if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
>  			dev->sda_hold_time |= 1 <<
> DW_IC_SDA_HOLD_RX_SHIFT;
> +
> +		dev_dbg(dev->dev, "SDA Hold Time TX:RX = %d:%d\n",
> +			dev->sda_hold_time &
> ~(u32)DW_IC_SDA_HOLD_RX_MASK,

I'm not sure I understand why you need casting here.

> +			dev->sda_hold_time >>
> DW_IC_SDA_HOLD_RX_SHIFT);

>  	} else if (dev->sda_hold_time) {
>  		dev_warn(dev->dev,
>  			"Hardware too old to adjust SDA hold
> time.\n");

-- 
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy



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