Re: [PATCH v6 1/3] hwmon: it87: describe per-chip temperature resources

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The driver queries extended temperature limits and offsets for channels 4-6 from the hardware but fails to expose them in sysfs, making the newly added feature inaccessible to userspace.
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commit a00b7b5308a4440e2558cdfeab430801514fd5ce
Author: benoit.masson <yahoo@perenite.com>

    hwmon: it87: describe per-chip temperature resources
    
    Add per-chip temp limit/offset/map counts and wire the driver
    to use them.
    
    This keeps existing chips on the previous defaults while allowing newer
    chips to advertise larger resources.

> diff --git a/drivers/hwmon/it87.c b/drivers/hwmon/it87.c
> index 87edb1b6048bb..1af815b5d33a9 100644
> --- a/drivers/hwmon/it87.c
> +++ b/drivers/hwmon/it87.c
[ ... ]
> @@ -379,18 +397,24 @@ static const struct it87_devices it87_devices[] = {
>  		.name = "it8728",
>  		.model = "IT8728F",
>  		.features = FEAT_NEWER_AUTOPWM | FEAT_12MV_ADC | FEAT_16BIT_FANS
> -		  | FEAT_TEMP_OFFSET | FEAT_TEMP_PECI | FEAT_FIVE_FANS
> +		  | FEAT_TEMP_PECI | FEAT_FIVE_FANS
>  		  | FEAT_IN7_INTERNAL | FEAT_PWM_FREQ2
>  		  | FEAT_FANCTL_ONOFF,
> +		.num_temp_limit = 6,

[Severity: Medium]
With num_temp_limit updated to 6 for newer chips to support reading
temperature limits and offsets for channels 4-6 from the hardware, do these
new attributes need to be exposed to userspace?

The driver's sysfs mapping array statically lacks limit and offset
attributes for temp4-6:

drivers/hwmon/it87.c:it87_attributes_temp[] {
    ...
	&sensor_dev_attr_temp4_input.dev_attr.attr,	/* 21 */
	&sensor_dev_attr_temp5_input.dev_attr.attr,
	&sensor_dev_attr_temp6_input.dev_attr.attr,
	NULL
}

Additionally, the hardcoded logic in it87_temp_is_visible() restricts these
attributes:

drivers/hwmon/it87.c:it87_temp_is_visible() {
    ...
	if (index >= 21) {
		i = index - 21 + 3;
		a = 0;
	}
    ...
}

This logic forces a = 0 (input) for all attributes beyond index 21, which
structurally prevents the visibility of min, max, or offset attributes for
temp 4-6 even if they were appended to the array.

Does the sysfs attribute mapping and visibility logic need to be updated so
that userspace can access the newly queried hardware limits?

> +		.num_temp_offset = 3,
> +		.num_temp_map = 3,
>  		.peci_mask = 0x07,
>  	},

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Sashiko AI review · https://sashiko.dev/#/patchset/20260829210036.61136-1-jerome.tollet@gmail.com?part=1