Re: [PATCH v3] hwmon: (lm75) Add support for Nuvoton NCT7715

[off-list ref] 於 2026年9月15日週二 下午1:28寫道：

quoted

+     [nct7715] = {
+             .config_reg_16bits = true,
+             .set_mask = 0x8060,     /* 12-bit mode, 4 samples / second */
+             .clr_mask = 1 << 7,     /* no one-shot mode */

[Severity: Medium]
Will this leave bit 14 unchanged if it was previously set by a bootloader or
left over from a warm reboot?

During driver probe, lm75_generic_probe() calls lm75_write_config() to
initialize LM75_REG_CONF. The regmap update mask used is:
clr_mask | set_mask | LM75_SHUTDOWN

For nct7715, set_mask is 0x8060 and clr_mask is 0x0080. Bit 14 (0x4000) is
missing from both masks. Because of this, regmap_update_bits() will
silently ignore the 0 in bit 14 of set_mask and preserve its prior value
from the hardware configuration register.

If bit 14 remains set, can the sensor operate at 8 Hz instead of the
intended 4 Hz, leading to a mismatch between the hardware state and the
driver state which expects and reports a 250ms interval?

Should 0x4000 be included in clr_mask to ensure the hardware is properly
initialized to 4 samples / second?

--
Sashiko AI review · https://sashiko.dev/#/patchset/20260915052021.6959-1-syhuang3@nuvoton.com?part=1

I will update the patch in v4 to include bit 14 in the NCT7715 clear
mask, ensuring that the default conversion rate is initialized to 4 Hz.