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If the write fails without changing the register, subsequent update_interval reads report the requested interval instead of the previous setting. Update interval_idx only after regmap_write() succeeds, leaving the previous cached interval in place on error. Fixes: e2fe950f34e5 ("hwmon: add support for MCP998X") Signed-off-by: Baek Kyu, Kim --- Tested under ARM64 QEMU with an emulated SMBus adapter through the hwmon sysfs interface. Rejected writes reproduce the incorrect interval; the fix retains the previous value. Successful writes, retries and MCP9982D's interval limit were also checked. No physical sensor was tested. drivers/hwmon/mcp9982.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/hwmon/mcp9982.c b/drivers/hwmon/mcp9982.c index 3918dc36c946..2cd41dcbd9af 100644 --- a/drivers/hwmon/mcp9982.c +++ b/drivers/hwmon/mcp9982.c @@ -624,6 +624,7 @@ static int mcp9982_write(struct device *dev, enum hwmon_sensor_types type, u32 a { struct mcp9982_priv *priv = dev_get_drvdata(dev); unsigned int idx; + int ret; u8 addr; switch (type) { @@ -640,9 +641,13 @@ static int mcp9982_write(struct device *dev, enum hwmon_sensor_types type, u32 a idx = find_closest_descending(val, mcp9982_update_interval, ARRAY_SIZE(mcp9982_update_interval)); + ret = regmap_write(priv->regmap, MCP9982_CONV_ADDR, idx); + if (ret) + return ret; + priv->interval_idx = idx; - return regmap_write(priv->regmap, MCP9982_CONV_ADDR, idx); + return 0; default: return -EINVAL; } base-commit: 58161ead29e50d70a317ea26b472e0c7508e69da -- 2.55.0