Comment 0 for bug 1514052

I have just upgraded to Ubuntu 15.10 and almost immediately my CPU fan started speeding and slowing without good reason even when the PC is idle.

I tried various things but then found that if I leave the computer off for a long time and let everything cool down then when I boot from cold the CPU fan is stable.

To test my theory of cold start out I then ran
sudo cpupower frequency-set -g powersave
followed by
sudo cpupower frequency-set -g ondemand

The final mode is the initial mode. Almost immediately as soon as I moved to powersave mode the erratic fan speed started. It did not stop when I returned to ondemand.

Temp fix for this behaviour is - go and have a cup of coffee and let the computer cool down when you restart: shutdown then start from cold.

$ uname -a
Linux HomeMegaUbuntu 4.2.0-17-generic #21-Ubuntu SMP Fri Oct 23 19:56:16 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 15.10
Release: 15.10
Codename: wily

$ cpupower frequency-info
analyzing CPU 0:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 10.0 us.
  hardware limits: 1.20 GHz - 2.80 GHz
  available frequency steps: 2.80 GHz, 2.80 GHz, 2.67 GHz, 2.53 GHz, 2.40 GHz, 2.27 GHz, 2.13 GHz, 2.00 GHz, 1.87 GHz, 1.73 GHz, 1.60 GHz, 1.47 GHz, 1.33 GHz, 1.20 GHz
  available cpufreq governors: conservative, ondemand, userspace, powersave, performance
  current policy: frequency should be within 1.20 GHz and 2.80 GHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency is 1.20 GHz.
  cpufreq stats: 2.80 GHz:11.93%, 2.80 GHz:0.00%, 2.67 GHz:0.40%, 2.53 GHz:0.44%, 2.40 GHz:0.51%, 2.27 GHz:0.55%, 2.13 GHz:0.35%, 2.00 GHz:0.72%, 1.87 GHz:0.84%, 1.73 GHz:1.00%, 1.60 GHz:2.16%, 1.47 GHz:4.61%, 1.33 GHz:16.83%, 1.20 GHz:59.65% (29241)
  boost state support:
    Supported: yes
    Active: yes
    25500 MHz max turbo 4 active cores
    25500 MHz max turbo 3 active cores
    25500 MHz max turbo 2 active cores
    25500 MHz max turbo 1 active cores

Tried intel_pstate but it is not supported for some reason on my machine ie the following does not work and I am left with driver: acpi-cpufreq

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash intel_pstate=enable"

Could not see ACPI Thermal Zones reported in dmesg
$ dmesg | grep ACPI
[ 0.000000] BIOS-e820: [mem 0x00000000bd780000-0x00000000bd78dfff] ACPI data
[ 0.000000] BIOS-e820: [mem 0x00000000bd78e000-0x00000000bd7cffff] ACPI NVS
[ 0.000000] ACPI: Early table checksum verification disabled
[ 0.000000] ACPI: RSDP 0x00000000000F9B40 000024 (v02 ACPIAM)
[ 0.000000] ACPI: XSDT 0x00000000BD780100 00006C (v01 DELL FX09 20101113 MSFT 00000097)
[ 0.000000] ACPI: FACP 0x00000000BD780290 0000F4 (v04 DELL FX09 20101113 MSFT 00000097)
[ 0.000000] ACPI BIOS Warning (bug): 32/64X length mismatch in FADT/Gpe0Block: 128/64 (20150619/tbfadt-623)
[ 0.000000] ACPI: DSDT 0x00000000BD780660 005B02 (v02 1AAAA 1AAAA000 00000000 INTL 20051117)
[ 0.000000] ACPI: FACS 0x00000000BD78E000 000040
[ 0.000000] ACPI: FACS 0x00000000BD78E000 000040
[ 0.000000] ACPI: APIC 0x00000000BD780390 00008C (v02 DELL FX09 20101113 MSFT 00000097)
[ 0.000000] ACPI: MCFG 0x00000000BD780420 00003C (v01 DELL OEMMCFG 20101113 MSFT 00000097)
[ 0.000000] ACPI: SLIC 0x00000000BD780460 000176 (v01 DELL FX09 20101113 MSFT 00000097)
[ 0.000000] ACPI: OSFR 0x00000000BD7805E0 000080 (v01 DELL FX09 20101113 MSFT 00000097)
[ 0.000000] ACPI: OEMB 0x00000000BD78E040 000072 (v01 DELL FX09 20101113 MSFT 00000097)
[ 0.000000] ACPI: HPET 0x00000000BD78A660 000038 (v01 DELL OEMHPET 20101113 MSFT 00000097)
[ 0.000000] ACPI: ASF! 0x00000000BD78A6A0 000099 (v32 LEGEND I865PASF 00000001 INTL 20051117)
[ 0.000000] ACPI: SSDT 0x00000000BD78F800 000363 (v01 DpgPmm CpuPm 00000012 INTL 20051117)
[ 0.000000] ACPI: Local APIC address 0xfee00000
[ 0.000000] ACPI: PM-Timer IO Port: 0x808
[ 0.000000] ACPI: Local APIC address 0xfee00000
[ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 2 dfl dfl)
[ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 high level)
[ 0.000000] ACPI: IRQ0 used by override.
[ 0.000000] ACPI: IRQ9 used by override.
[ 0.000000] Using ACPI (MADT) for SMP configuration information
[ 0.000000] ACPI: HPET id: 0x8086a701 base: 0xfed00000
[ 0.000048] ACPI: Core revision 20150619
[ 0.004019] ACPI: All ACPI Tables successfully acquired
[ 0.206757] PM: Registering ACPI NVS region [mem 0xbd78e000-0xbd7cffff] (270336 bytes)
[ 0.217768] ACPI FADT declares the system doesn't support PCIe ASPM, so disable it
[ 0.217775] ACPI: bus type PCI registered
[ 0.217780] acpiphp: ACPI Hot Plug PCI Controller Driver version: 0.5
[ 0.222002] ACPI: Added _OSI(Module Device)
[ 0.222007] ACPI: Added _OSI(Processor Device)
[ 0.222011] ACPI: Added _OSI(3.0 _SCP Extensions)
[ 0.222016] ACPI: Added _OSI(Processor Aggregator Device)
[ 0.223412] ACPI: Executed 1 blocks of module-level executable AML code
[ 0.224917] ACPI: Dynamic OEM Table Load:
[ 0.224929] ACPI: SSDT 0xFFFF8802370FE000 001238 (v01 DpgPmm P001Ist 00000011 INTL 20051117)
[ 0.225251] ACPI: Dynamic OEM Table Load:
[ 0.225259] ACPI: SSDT 0xFFFF880235D62000 0004F4 (v01 PmRef P001Cst 00003001 INTL 20051117)
[ 0.225623] ACPI: Interpreter enabled
[ 0.225631] ACPI Exception: AE_NOT_FOUND, While evaluating Sleep State [\_S1_] (20150619/hwxface-580)
[ 0.225641] ACPI Exception: AE_NOT_FOUND, While evaluating Sleep State [\_S2_] (20150619/hwxface-580)
[ 0.225659] ACPI: (supports S0 S3 S4 S5)
[ 0.225663] ACPI: Using IOAPIC for interrupt routing
[ 0.226463] PCI: MMCONFIG at [mem 0xe0000000-0xefffffff] reserved in ACPI motherboard resources
[ 0.226492] PCI: Using host bridge windows from ACPI; if necessary, use "pci=nocrs" and report a bug
[ 0.231375] ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff])
[ 0.232079] pci 0000:00:03.0: System wakeup disabled by ACPI
[ 0.232944] pci 0000:00:1a.0: System wakeup disabled by ACPI
[ 0.233219] pci 0000:00:1c.0: System wakeup disabled by ACPI
[ 0.233355] pci 0000:00:1c.5: System wakeup disabled by ACPI
[ 0.233524] pci 0000:00:1d.0: System wakeup disabled by ACPI
[ 0.233628] pci 0000:00:1e.0: System wakeup disabled by ACPI
[ 0.250257] ACPI: PCI Interrupt Link [LNKA] (IRQs 3 4 6 7 *10 11 12 14 15)
[ 0.250305] ACPI: PCI Interrupt Link [LNKB] (IRQs *5)
[ 0.250348] ACPI: PCI Interrupt Link [LNKC] (IRQs *3 4 6 7 10 11 12 14 15)
[ 0.250394] ACPI: PCI Interrupt Link [LNKD] (IRQs 3 4 6 7 10 *11 12 14 15)
[ 0.250440] ACPI: PCI Interrupt Link [LNKE] (IRQs 3 4 6 7 10 11 12 14 15) *0, disabled.
[ 0.250489] ACPI: PCI Interrupt Link [LNKF] (IRQs 3 4 6 7 10 11 12 14 15) *0, disabled.
[ 0.250538] ACPI: PCI Interrupt Link [LNKG] (IRQs 3 4 6 7 10 11 12 14 *15)
[ 0.250584] ACPI: PCI Interrupt Link [LNKH] (IRQs 3 4 6 7 10 11 12 *14 15)
[ 0.250633] ACPI: Enabled 2 GPEs in block 00 to 3F
[ 0.251003] ACPI: bus type USB registered
[ 0.251169] PCI: Using ACPI for IRQ routing
[ 0.256895] ACPI: \: failed to evaluate _DSM (0x1001)
[ 0.265257] pnp: PnP ACPI init
[ 0.265351] system 00:00: Plug and Play ACPI device, IDs PNP0c01 (active)
[ 0.265407] pnp 00:01: Plug and Play ACPI device, IDs PNP0b00 (active)
[ 0.265587] system 00:02: Plug and Play ACPI device, IDs PNP0c02 (active)
[ 0.265738] system 00:03: Plug and Play ACPI device, IDs PNP0c02 (active)
[ 0.265823] system 00:04: Plug and Play ACPI device, IDs PNP0c02 (active)
[ 0.265919] system 00:05: Plug and Play ACPI device, IDs PNP0c02 (active)
[ 0.265982] system 00:06: Plug and Play ACPI device, IDs PNP0c02 (active)
[ 0.266159] system 00:07: Plug and Play ACPI device, IDs PNP0c01 (active)
[ 0.266252] pnp: PnP ACPI: found 8 devices
[ 1.168433] ACPI: Power Button [PWRB]
[ 1.170665] ACPI: Power Button [PWRF]
[ 21.995925] ACPI Warning: SystemIO range 0x0000000000000828-0x000000000000082F conflicts with OpRegion 0x0000000000000800-0x000000000000084F (\PMRG) (20150619/utaddress-254)
[ 21.995931] ACPI: If an ACPI driver is available for this device, you should use it instead of the native driver