Hi Guenter,
On 6/28/24 5:13 PM, Guenter Roeck wrote:
The default value of the maximum fan speed limit register is 0,
essentially translating to an unlimited fan speed. When reading
the limit, a value of 0 is reported in this case. However, writing
a value of 0 results in writing a value of 0xffff into the register,
which is inconsistent.
> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
drivers/hwmon/amc6821.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/hwmon/amc6821.c b/drivers/hwmon/amc6821.c
index 3c614a0bd192..e37257ae1a6b 100644
--- a/drivers/hwmon/amc6821.c
+++ b/drivers/hwmon/amc6821.c
@@ -601,7 +601,7 @@ static ssize_t fan_show(struct device *dev, struct device_attribute *devattr,
struct amc6821_data *data = amc6821_update_device(dev);
int ix = to_sensor_dev_attr(devattr)->index;
if (0 == data->fan[ix])
- return sprintf(buf, "0");
+ return sprintf(buf, "6000000");
return sprintf(buf, "%d\n", (int)(6000000 / data->fan[ix]));
}
@@ -625,10 +625,10 @@ static ssize_t fan_store(struct device *dev, struct device_attribute *attr,
int ret = kstrtol(buf, 10, &val);
if (ret)
return ret;
- val = 1 > val ? 0xFFFF : 6000000/val;
+ val = val < 1 ? 0xFFFF : 6000000 / val;
mutex_lock(&data->update_lock);
- data->fan[ix] = (u16) clamp_val(val, 1, 0xFFFF);
+ data->fan[ix] = (u16)clamp_val(val, 0, 0xFFFF);
This is an unrelated change I believe and I would therefore have this in
its own commit with proper documentation in the commit log. Indeed:
1- Change in fan_show handles the default 0x0 register value (which can
only currently be achieved via the default value of the registers)
2- Allow (re-)setting unlimited fan speed by allowing the user to pass
6000001+ instead of clamping it to 6000000 RPM.
Looking good otherwise,
Cheers,
Quentin
