Hi Brian, On Mon, 2 Dec 2013 10:17:56 +0100, Jean Delvare wrote: > If I'm not mistaken, the following minimal fix should work: > > From: Jean Delvare <khali@xxxxxxxxxxxx> > Subject: hwmon: (w83l768ng) Fix fan speed control range > > The W83L786NG stores the fan speed on 4 bits while the sysfs interface > uses a 0-255 range. Thus the driver should scale the user input down > to map it to the device range, and scale up the value read from the > device before presenting it to the user. > > Signed-off-by: Jean Delvare <khali@xxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > --- > drivers/hwmon/w83l786ng.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > --- linux-3.13-rc2.orig/drivers/hwmon/w83l786ng.c 2013-12-02 09:14:56.247009803 +0100 > +++ linux-3.13-rc2/drivers/hwmon/w83l786ng.c 2013-12-02 10:07:49.718037923 +0100 > @@ -481,6 +481,7 @@ store_pwm(struct device *dev, struct dev > if (err) > return err; > val = clamp_val(val, 0, 255); > + val = DIV_ROUND_CLOSEST(val, 0x11); > > mutex_lock(&data->update_lock); > data->pwm[nr] = val; > @@ -777,8 +778,9 @@ static struct w83l786ng_data *w83l786ng_ > ? 0 : 1; > data->pwm_enable[i] = > ((pwmcfg >> W83L786NG_PWM_ENABLE_SHIFT[i]) & 3) + 1; > - data->pwm[i] = w83l786ng_read_value(client, > - W83L786NG_REG_PWM[i]); > + data->pwm[i] = > + (w83l786ng_read_value(client, W83L786NG_REG_PWM[i]) > + & 0x0f) * 0x11; > } > > > Please test and confirm. I was actually mistaken, my patch had a minor flaw that caused the driver to temporarily return the wrong pwmN value right after setting it. Additionally it was overwriting reserved bits in registers W83L786NG_REG_PWM, which is bad. Patch V2 below fixes both issues: From: Jean Delvare <khali@xxxxxxxxxxxx> Subject: hwmon: (w83l768ng) Fix fan speed control range The W83L786NG stores the fan speed on 4 bits while the sysfs interface uses a 0-255 range. Thus the driver should scale the user input down to map it to the device range, and scale up the value read from the device before presenting it to the user. The reserved register nibble should be left unchanged. Signed-off-by: Jean Delvare <khali@xxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx --- Changes in v2: * Scale data->pwm[nr] up when writing a new value to the W83L786NG_REG_PWM[nr] register. * Don't overwrite the 4 MSB of W83L786NG_REG_PWM. drivers/hwmon/w83l786ng.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- linux-3.13-rc3.orig/drivers/hwmon/w83l786ng.c 2013-12-11 15:01:33.162221180 +0100 +++ linux-3.13-rc3/drivers/hwmon/w83l786ng.c 2013-12-11 15:22:36.004771774 +0100 @@ -481,9 +481,11 @@ store_pwm(struct device *dev, struct dev if (err) return err; val = clamp_val(val, 0, 255); + val = DIV_ROUND_CLOSEST(val, 0x11); mutex_lock(&data->update_lock); - data->pwm[nr] = val; + data->pwm[nr] = val * 0x11; + val |= w83l786ng_read_value(client, W83L786NG_REG_PWM[nr]) & 0xf0; w83l786ng_write_value(client, W83L786NG_REG_PWM[nr], val); mutex_unlock(&data->update_lock); return count; @@ -777,8 +779,9 @@ static struct w83l786ng_data *w83l786ng_ ? 0 : 1; data->pwm_enable[i] = ((pwmcfg >> W83L786NG_PWM_ENABLE_SHIFT[i]) & 3) + 1; - data->pwm[i] = w83l786ng_read_value(client, - W83L786NG_REG_PWM[i]); + data->pwm[i] = + (w83l786ng_read_value(client, W83L786NG_REG_PWM[i]) + & 0x0f) * 0x11; } Again, testing would be appreciated. Thanks, -- Jean Delvare _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
