On Fri, Nov 30, 2018 at 03:44:08PM +0000, Michele Sorcinelli wrote:
> Reviewed by: Pali Rohár <pali.rohar@xxxxxxxxx>
>
This is not where to put a Reviewed-by: tag, and the patch is
not signed and thus can not be applied.
> Allow the module to be loaded on Dell XPS 9570, without having to use
> the "force=1" option. The module loads without problems, and reports
> correct values:
>
> $ time cat /proc/i8k
> 1.0 1.5 -1 35 0 0 0 0 -1 -22
> cat /proc/i8k 0.00s user 0.00s system 7% cpu 0.033 total
>
> However, the call may freeze the kernel for a very small time due to
> code running in the SSM layer. This is a known issue with the driver, and
> can be reproduced with other supported models. Average execution
> time is 33 ms.
Is it ? My understanding is that it is an issue with the SMM layer.
If you have actual evidence that the problem lies within the driver,
not with SMM, please share that information.
>
> The command line tools from i8kutils can properly set the fan speed,
> although the firmware will override it, unless automatic fan
> control is disabled with the proper SSM call.
>
> Average fans speed (when firwmare automatic control is off):
>
> STATE -> RPM
> 0 0 -> 0 0
> 1 1 -> 2500 2500
> 2 2 -> 5100 5100
> 3 3 -> same as 2 2
>
> The SSM procedures I8K_SMM_GET_FAN_TYPE and I8K_SMM_GET_TEMP_TYPE are
> failing to return valid values to the module, that can't label the fans
> and initialize the temperature sensors in the hwmon interface.
>
> This is a problem in the firmware code, and may be eventually addressed
> by a new firmware version.
>
> $ sensors dell_smm-virtual-0
> dell_smm-virtual-0
> Adapter: Virtual device
> fan1: 2531 RPM
> fan2: 2496 RPM
>
> However, the procedures I8K_SMM_GET_FAN and I8K_SMM_GET_TEMP are working
> properly, as they return correct values. This means that the module
> could be modified to initialize the sensors without labels and report
> correct temperatures.
This is a different problem, not part of this patch, and the information
does not belong here.
Guenter
> ---
> drivers/hwmon/dell-smm-hwmon.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
> index 9d3ef879d..367a8a617 100644
> --- a/drivers/hwmon/dell-smm-hwmon.c
> +++ b/drivers/hwmon/dell-smm-hwmon.c
> @@ -1017,6 +1017,13 @@ static const struct dmi_system_id i8k_dmi_table[] __initconst = {
> DMI_MATCH(DMI_PRODUCT_NAME, "XPS 15 9560"),
> },
> },
> + {
> + .ident = "Dell XPS 15 9570",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
> + DMI_MATCH(DMI_PRODUCT_NAME, "XPS 15 9570"),
> + },
> + },
> { }
> };
>
> --
> 2.19.2
>
