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Groups > linux.kernel > #1409227
| From | Gabriele Mazzotta <gabriele.mzt@gmail.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [Experimental PATCH] dell-smm-hwmon: Add support for disabling automatic BIOS fan control |
| Date | 2016-05-30 17:30 +0200 |
| Message-ID | <rExiF-5ZF-3@gated-at.bofh.it> (permalink) |
| References | <rBAd3-kh-9@gated-at.bofh.it> <rDoUa-3jS-7@gated-at.bofh.it> <rErQ3-2lt-21@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 30/05/2016 11:32, Pali Rohár wrote: > On Friday 27 May 2016 14:11:11 Gabriele Mazzotta wrote: >> On 22/05/2016 13:50, Pali Rohár wrote: >>> This patch exports standard hwmon pwmX_enable sysfs attribute for enabling >>> or disabling automatic fan control by BIOS. Standard value "1" is for >>> disabling automatic BIOS fan control and value "2" for enabling. >>> >>> Currently there is no way to check if BIOS auto mode is enabled (at least >>> it is not know how to do it), so hwmon sysfs attribute is write-only. >>> >>> By default BIOS auto mode is enabled by laptop firmware. >>> >>> When BIOS auto mode is enabled, custom fan speed value (set via hwmon pwmX >>> sysfs attribute) is overwritten by SMM in few seconds and therefore any >>> custom settings are without effect. So this is reason why implementing >>> option for disabling BIOS auto mode is needed. >>> >>> So finally this patch allows kernel to set and control fan speed on >>> laptops, but it can be dangerous (like setting speed of other fans). >>> >>> This new feature is highly experimental, uses Dell SMM calls, so does not >>> have to be supported by all laptops BIOSes. It was tested on Dell Latitude >>> E6440 with BIOS A5. >> >> Tested on a Dell XPS13 9333. Changing the value of pwm1_enable appears >> to have no effect here. > > Can you check what i8k_enable_fan_auto_mode() returns? Error code or not? No error. However, independently on the value I set, the BIOS always overrides the speed of the fan.
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[Experimental PATCH] dell-smm-hwmon: Add support for disabling automatic BIOS fan control Pali Rohár <pali.rohar@gmail.com> - 2016-05-22 14:00 +0200
Re: [Experimental PATCH] dell-smm-hwmon: Add support for disabling automatic BIOS fan control Guenter Roeck <linux@roeck-us.net> - 2016-05-22 17:10 +0200
Re: [Experimental PATCH] dell-smm-hwmon: Add support for disabling automatic BIOS fan control Pali Rohár <pali.rohar@gmail.com> - 2016-05-22 17:20 +0200
Re: [Experimental PATCH] dell-smm-hwmon: Add support for disabling automatic BIOS fan control Guenter Roeck <linux@roeck-us.net> - 2016-05-22 17:30 +0200
Re: [Experimental PATCH] dell-smm-hwmon: Add support for disabling automatic BIOS fan control Gabriele Mazzotta <gabriele.mzt@gmail.com> - 2016-05-27 14:20 +0200
Re: [Experimental PATCH] dell-smm-hwmon: Add support for disabling automatic BIOS fan control Pali Rohár <pali.rohar@gmail.com> - 2016-05-30 11:40 +0200
Re: [Experimental PATCH] dell-smm-hwmon: Add support for disabling automatic BIOS fan control Gabriele Mazzotta <gabriele.mzt@gmail.com> - 2016-05-30 17:30 +0200
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