On Saturday 14 August 2021 16:36:36 W_Armin@xxxxxx wrote: > From: Armin Wolf <W_Armin@xxxxxx> > > Add automatic fan speed control for the remaining two pwm channels > since the pwmX_enable setting affects all pwm channels. > > Signed-off-by: Armin Wolf <W_Armin@xxxxxx> This behavior was already rejected by Guenter: https://lore.kernel.org/linux-hwmon/3a10f96a-06e1-39f4-74a6-908d25b1f496@xxxxxxxxxxxx/ "Having three attributes do all the same is not very valuable. I would suggest to stick with pwm1_enable and document that it applies to all pwm channels." > --- > Documentation/hwmon/dell-smm-hwmon.rst | 14 +++++++------- > drivers/hwmon/dell-smm-hwmon.c | 4 ++-- > 2 files changed, 9 insertions(+), 9 deletions(-) > > diff --git a/Documentation/hwmon/dell-smm-hwmon.rst b/Documentation/hwmon/dell-smm-hwmon.rst > index 3bf77a5df995..57b30fc9d03a 100644 > --- a/Documentation/hwmon/dell-smm-hwmon.rst > +++ b/Documentation/hwmon/dell-smm-hwmon.rst > @@ -35,7 +35,7 @@ Name Perm Description > fan[1-3]_input RO Fan speed in RPM. > fan[1-3]_label RO Fan label. > pwm[1-3] RW Control the fan PWM duty-cycle. > -pwm1_enable WO Enable or disable automatic BIOS fan > +pwm[1-3]_enable WO Enable or disable automatic BIOS fan > control (not supported on all laptops, > see below for details). > temp[1-10]_input RO Temperature reading in milli-degrees > @@ -52,13 +52,13 @@ overwritten. > > There is experimental support for disabling automatic BIOS fan > control, at least on laptops where the corresponding SMM command is > -known, by writing the value ``1`` in the attribute ``pwm1_enable`` > -(writing ``2`` enables automatic BIOS control again). Even if you have > +known, by writing the value ``1`` in the attribute ``pwm[1-3]_enable`` > +(writing ``2`` enables automatic BIOS control again). If you have > more than one fan, all of them are set to either enabled or disabled > -automatic fan control at the same time and, notwithstanding the name, > -``pwm1_enable`` sets automatic control for all fans. > +automatic fan control at the same time so ``pwm[1-3]_enable`` > +sets automatic fan control for **all** fans. > > -If ``pwm1_enable`` is not available, then it means that SMM codes for > +If ``pwm[1-3]_enable`` is not available, then it means that SMM codes for > enabling and disabling automatic BIOS fan control are not whitelisted > for your hardware. It is possible that codes that work for other > laptops actually work for yours as well, or that you have to discover > @@ -67,7 +67,7 @@ new codes. > Check the list ``i8k_whitelist_fan_control`` in file > ``drivers/hwmon/dell-smm-hwmon.c`` in the kernel tree: as a first > attempt you can try to add your machine and use an already-known code > -pair. If, after recompiling the kernel, you see that ``pwm1_enable`` > +pair. If, after recompiling the kernel, you see that ``pwm[1-3]_enable`` > is present and works (i.e., you can manually control the fan speed), > then please submit your finding as a kernel patch, so that other users > can benefit from it. Please see > diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c > index 3aa09c1e4b1d..0e229e3dae33 100644 > --- a/drivers/hwmon/dell-smm-hwmon.c > +++ b/drivers/hwmon/dell-smm-hwmon.c > @@ -898,8 +898,8 @@ static const struct hwmon_channel_info *dell_smm_info[] = { > ), > HWMON_CHANNEL_INFO(pwm, > HWMON_PWM_INPUT | HWMON_PWM_ENABLE, > - HWMON_PWM_INPUT, > - HWMON_PWM_INPUT > + HWMON_PWM_INPUT | HWMON_PWM_ENABLE, > + HWMON_PWM_INPUT | HWMON_PWM_ENABLE > ), > NULL > }; > -- > 2.20.1 >
