Re: [PATCH 1/7] thermal: rcar_gen3_thermal: add delay in .thermal_init on r8a7796

["Niklas Söderlund" <niklas.soderlund@ragnatech.se>]

On 2017-03-06 21:03:55 +0100, Niklas Söderlund wrote:
> The .thermal_init needs to be delayed a short amount of to allow for the
> TEMP register to contain something useful. If it's not delayed theses
> warnings are common during boot:
> 
> thermal thermal_zone0: failed to read out thermal zone (-5)
> thermal thermal_zone1: failed to read out thermal zone (-5)
> thermal thermal_zone2: failed to read out thermal zone (-5)
> 
> The warnings are triggered by the first call to .get_temp while the TEMP
> register contains 0 and rcar_gen3_thermal_get_temp() returns -EIO since
> a TEMP value of 0 will result in a temperature reading which is out of
> specifications.
> 
> This should have been done in the initial commit which adds the driver
> as the same issue was found and corrected for r8a7795.
> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

I forgot this tag for this patch, will update if there is a need for v2.

Fixes: 564e73d283af9d4c ("thermal: rcar_gen3_thermal: Add R-Car Gen3 thermal driver")

> ---
>  drivers/thermal/rcar_gen3_thermal.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/thermal/rcar_gen3_thermal.c b/drivers/thermal/rcar_gen3_thermal.c
> index d33c845244b1d819..ec477d47d0bae8e5 100644
> --- a/drivers/thermal/rcar_gen3_thermal.c
> +++ b/drivers/thermal/rcar_gen3_thermal.c
> @@ -222,6 +222,8 @@ static void r8a7796_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
>  	reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
>  	reg_val |= THCTR_THSST;
>  	rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
> +
> +	usleep_range(1000, 2000);
>  }
>  
>  static const struct rcar_gen3_thermal_data r8a7795_data = {
> -- 
> 2.12.0
> 

-- 
Regards,
Niklas Söderlund