Re: [RFT PATCH 3/3] hwmon: (nct6775) Fix tolerance bitmask when reading REG_FAN_MODE

[sashiko-bot@kernel.org]

> On NCT6775, bits 0..3 of REG_FAN_MODE hold the temperature or fan speed
> tolerance (tolerance_mask is 0x0f), whereas on NCT5525, NCT6106,
> NCT6116, NCT6126, and NCT6776+, only bits 0..2 hold the temperature
> tolerance or low 3 bits of speed tolerance (tolerance_mask is 0x07).
> However, nct6775_update_pwm() masks fanmodecfg with a hardcoded 0x0f.
> 
> When bit 3 of REG_FAN_MODE is set on chips where tolerance_mask is 0x07,
> nct6775_update_pwm() includes bit 3 in temp_tolerance[0] and
> target_speed_tolerance, corrupting reported tolerance values and causing
> pwm_update_registers() to OR bit 3 back into REG_FAN_MODE.
> 
> Mask fanmodecfg with data->tolerance_mask instead of 0x0f in
> nct6775_update_pwm().
> 
> Fixes: cdcaeceb74ff ("hwmon: (nct6775) Add support for automatic fan control")
> Reported-by: Sashiko <sashiko-bot@kernel.org>
> Link: https://sashiko.dev
> Cc: Anton Lundin <glance@ac2.se>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Sashiko has reviewed this patch and found no issues.

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