Re: [PATCH] hwmon: (dell-smm) Add Dell Precision 3650 Tower to fan control whitelist

[Pali Rohár]

On Sunday 13 September 2026 11:29:25 Patrick Pepin wrote:
> On the Dell Precision 3650 Tower, the EC ignores fan speed writes unless
> automatic BIOS fan control is disabled first. The same SMM code pair as
> the OptiPlex 7000 (I8K_FAN_34A3_35A3) works on this machine through the
> WMI-SMM backend: after writing 1 to pwm1_enable, all three fans (CPU,
> front, top) accept the three fan states and report matching RPM.
> 
> Tested on BIOS 1.48.0 with kernels 7.0.0-30 and 7.0.0-31 (Ubuntu 26.04).
> 
> Signed-off-by: Patrick Pepin <patpep@xxxxxx>

Acked-by: Pali Rohár <pali@xxxxxxxxxx>

> ---
>  drivers/hwmon/dell-smm-hwmon.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
> index 7ed94a3db..47668634f 100644
> --- a/drivers/hwmon/dell-smm-hwmon.c
> +++ b/drivers/hwmon/dell-smm-hwmon.c
> @@ -1639,6 +1639,14 @@ static const struct dmi_system_id i8k_whitelist_fan_control[] __initconst = {
>  		},
>  		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
>  	},
> +	{
> +		.ident = "Dell Precision 3650 Tower",
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
> +			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 3650 Tower"),
> +		},
> +		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
> +	},
>  	{
>  		.ident = "Dell Optiplex 7090",
>  		.matches = {
> -- 
> 2.53.0
>