Re: [PATCH v7 01/15] drm/xe/hwmon: Handle pcode read failures of xe_hwmon_pcode_rmw_power_limit

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] drm/xe/hwmon: error code from pcode write is dropped and replaced with -EIO
--

commit a3216689f81fc9f531bd48c8af3db490de1c046b
Author: Karthik Poosa <karthik.poosa@intel.com>
drm/xe/hwmon: Handle pcode read failures of xe_hwmon_pcode_rmw_power_limit

This commit adds error checking to pcode read operations in
xe_hwmon_pcode_rmw_power_limit() and propagates the error up to the callers.
Callers are updated to handle the new return values instead of continuing
with invalid data.

> diff --git a/drivers/gpu/drm/xe/xe_hwmon.c b/drivers/gpu/drm/xe/xe_hwmon.c
> index 5edeac961ec33..92be71f7bc92f 100644
> --- a/drivers/gpu/drm/xe/xe_hwmon.c
> +++ b/drivers/gpu/drm/xe/xe_hwmon.c

[ ... ]

> @@ -679,15 +683,18 @@ xe_hwmon_power_max_interval_store(struct device *dev, struct device_attribute *a
>  
>  	mutex_lock(&hwmon->hwmon_lock);
>  
> -	if (hwmon->xe->info.has_mbx_power_limits)
> -		xe_hwmon_pcode_rmw_power_limit(hwmon, power_attr, channel, PWR_LIM_TIME, rxy);
> -	else
> +	ret = count;
> +	if (hwmon->xe->info.has_mbx_power_limits) {
> +		if (xe_hwmon_pcode_rmw_power_limit(hwmon, power_attr, channel, PWR_LIM_TIME, rxy))
> +			ret = -EIO;

[Severity: Low]
Does this code intentionally discard the specific error code returned by
xe_hwmon_pcode_rmw_power_limit()?

Replacing the actual error (such as -ETIMEDOUT or -ENXIO) with a generic -EIO
might obscure the true cause of the hardware failure and affect userspace
retry logic. Can the returned error code be propagated directly instead?

> +	} else {
>  		r = xe_mmio_rmw32(mmio, xe_hwmon_get_reg(hwmon, REG_PKG_RAPL_LIMIT, channel),
>  				  PWR_LIM_TIME, rxy);
> +	}
>  
>  	mutex_unlock(&hwmon->hwmon_lock);
>  
> -	return count;
> +	return ret;
>  }

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261001195033.3466205-1-karthik.poosa@intel.com?part=1