RE: [PATCH v1 1/1] i2c: designware: Adjust bus_freq_hz when refuse high speed mode set

[Song Bao Hua (Barry Song)]

> -----Original Message-----
> From: Andy Shevchenko [mailto:andriy.shevchenko@xxxxxxxxxxxxxxx]
> Sent: Thursday, April 1, 2021 12:05 AM
> To: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>; Serge Semin
> <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>; linux-i2c@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx
> Cc: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>; Mika Westerberg
> <mika.westerberg@xxxxxxxxxxxxxxx>; wsa@xxxxxxxxxx; yangyicong
> <yangyicong@xxxxxxxxxx>; Song Bao Hua (Barry Song) <song.bao.hua@xxxxxxxxxxxxx>
> Subject: [PATCH v1 1/1] i2c: designware: Adjust bus_freq_hz when refuse high
> speed mode set
> 
> When hardware doesn't support High Speed Mode, we forget bus_freq_hz
> timing adjustment. This makes the timings and real registers being
> unsynchronized. Adjust bus_freq_hz when refuse high speed mode set.
> 
> Fixes: b6e67145f149 ("i2c: designware: Enable high speed mode")
> Reported-by: "Song Bao Hua (Barry Song)" <song.bao.hua@xxxxxxxxxxxxx>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---

Thanks for fixing that.

Reviewed-by: Barry Song <song.bao.hua@xxxxxxxxxxxxx>

>  drivers/i2c/busses/i2c-designware-master.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/i2c/busses/i2c-designware-master.c
> b/drivers/i2c/busses/i2c-designware-master.c
> index 34bb4e21bcc3..9bfa06e31eec 100644
> --- a/drivers/i2c/busses/i2c-designware-master.c
> +++ b/drivers/i2c/busses/i2c-designware-master.c
> @@ -129,6 +129,7 @@ static int i2c_dw_set_timings_master(struct dw_i2c_dev
> *dev)
>  		if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK)
>  			!= DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) {
>  			dev_err(dev->dev, "High Speed not supported!\n");
> +			t->bus_freq_hz = I2C_MAX_FAST_MODE_FREQ;
>  			dev->master_cfg &= ~DW_IC_CON_SPEED_MASK;
>  			dev->master_cfg |= DW_IC_CON_SPEED_FAST;
>  			dev->hs_hcnt = 0;
> --
> 2.30.2