Re: [PATCH 1/3] hwmon: spd5118: Do not fail resume on temporary I2C errors

[Guenter Roeck]

On 1/10/26 09:19, Tinsae Tadesse wrote:
> SPD5118 DDR5 temperature sensors may be temporarily unavailable
> during s2idle resume. Ignore temporary -ENXIO and -EIO errors during resume and allow
> register synchronization to be retried later.
>
> Signed-off-by: Tinsae Tadesse <tinsaetadesse2015@xxxxxxxxx>
> ---
>   drivers/hwmon/spd5118.c | 8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hwmon/spd5118.c b/drivers/hwmon/spd5118.c
> index 5da44571b6a0..ec9f14f6e0df 100644
> --- a/drivers/hwmon/spd5118.c
> +++ b/drivers/hwmon/spd5118.c
> @@ -512,9 +512,15 @@ static int spd5118_resume(struct device *dev)
>   {
>   	struct spd5118_data *data = dev_get_drvdata(dev);
>   	struct regmap *regmap = data->regmap;
> +	int ret;
>   
>   	regcache_cache_only(regmap, false);
> -	return regcache_sync(regmap);
> +	ret = regcache_sync(regmap);
> +	if(ret == -ENXIO || ret == -EIO) {
> +		dev_warn(dev, "SPD hub not responding on resume (%d), deferring init\n", ret);
> +		return 0;
> +	}
> +	return ret;
>   }
>   
>   static DEFINE_SIMPLE_DEV_PM_OPS(spd5118_pm_ops, spd5118_suspend, spd5118_resume);


Based on the subsequent exchange, this is not the appropriate solution.
The problem is that the i2c controller suspends too early. It should suspend
later instead. Alternatively, this driver should suspend early, but it does
not look like respective PM operations are available.

I would suggest to try replacing DEFINE_SIMPLE_DEV_PM_OPS() in drivers/i2c/busses/i2c-i801.c
with SET_LATE_SYSTEM_SLEEP_PM_OPS() or similar.

Guenter