On Fri, 2018-06-01 at 16:47 +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.
>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
with a caveat that explicit casting like other proposed (by me)
solutions are not ideal, so, let's stick with this one for now.
> 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 1b542d3e5a2e..1742f1910cfd 100644
> --- a/drivers/i2c/busses/i2c-designware-common.c
> +++ b/drivers/i2c/busses/i2c-designware-common.c
> @@ -209,6 +209,10 @@ 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,
> + 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
