作为背景，我想了解为什么我的笔记本电脑在使用交流电源时风扇总是转。
我安装并运行了该powertop工具。
powertop我注意到，当我从电池电源切换到主电源时，各种“可调”项目显示从“好”到“坏”的切换。
我的问题是：为什么powertop从电池切换到主电源时，可调项目会从“好”切换到“坏”？
（...这能解释为什么风扇一直开着吗？）
笔记本电脑是戴尔 precision 5520，运行 Ubuntu 20.04。tlp已安装电池电源管理实用程序。
进一步的详细信息，以下是在交流电下运行时 powertop 的可调参数选项卡下列出的内容：
>> Bad Enable SATA link power management for host0
Bad Enable SATA link power management for host1
Bad Enable Audio codec power management
Bad Runtime PM for I2C Adapter i2c-5 (i915 gmbus dpd)
Bad Runtime PM for I2C Adapter i2c-0 (SMBus I801 adapter at f040)
Bad Runtime PM for I2C Adapter i2c-3 (i915 gmbus dpc)
Bad Runtime PM for I2C Adapter i2c-4 (i915 gmbus dpb)
Bad Runtime PM for PCI Device Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Thermal Subsystem
Bad Runtime PM for PCI Device Intel Corporation 100 Series/C230 Series Chipset Family SMBus
Bad Runtime PM for PCI Device Intel Corporation 100 Series/C230 Series Chipset Family USB 3.0 xHCI Controller
Bad Runtime PM for PCI Device Intel Corporation HD Graphics 630
Bad Runtime PM for PCI Device Intel Corporation 100 Series/C230 Series Chipset Family Serial IO I2C Controller #0
Bad Runtime PM for PCI Device Intel Corporation 100 Series/C230 Series Chipset Family Thermal Subsystem
Bad Runtime PM for PCI Device Intel Corporation CM238 HD Audio Controller
Bad Runtime PM for PCI Device Intel Corporation Wireless 8265 / 8275
Bad Runtime PM for PCI Device Intel Corporation CM238 Chipset LPC/eSPI Controller
Bad Runtime PM for PCI Device Intel Corporation 100 Series/C230 Series Chipset Family Serial IO I2C Controller #1
Bad Runtime PM for PCI Device Intel Corporation 100 Series/C230 Series Chipset Family Power Management Controller
Bad Runtime PM for PCI Device Realtek Semiconductor Co., Ltd. RTS525A PCI Express Card Reader
Bad Runtime PM for PCI Device Intel Corporation Q170/Q150/B150/H170/H110/Z170/CM236 Chipset SATA Controller [AHCI Mode]
Bad Runtime PM for PCI Device Intel Corporation Xeon E3-1200 v6/7th Gen Core Processor Host Bridge/DRAM Registers
Good NMI watchdog should be turned off
Good VM writeback timeout
Good Bluetooth device interface status
Good Runtime PM for I2C Adapter i2c-2 (Synopsys DesignWare I2C adapter)
Good Autosuspend for USB device Integrated_Webcam_HD [CN045G28LOG00815B9B6A01]
Good Runtime PM for I2C Adapter i2c-1 (Synopsys DesignWare I2C adapter)
Good Autosuspend for USB device xHCI Host Controller [usb1]
Good Autosuspend for unknown USB device 1-4 (8087:0a2b)
Good Autosuspend for USB device xHCI Host Controller [usb2]
Good Runtime PM for PCI Device Intel Corporation 100 Series/C230 Series Chipset Family PCI Express Root Port #1
Good Runtime PM for port ata1 of PCI device: Intel Corporation Q170/Q150/B150/H170/H110/Z170/CM236 Chipset SATA Controller [AHCI Mode]
Good Runtime PM for PCI Device Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor PCIe Controller (x16)
Good Runtime PM for port ata2 of PCI device: Intel Corporation Q170/Q150/B150/H170/H110/Z170/CM236 Chipset SATA Controller [AHCI Mode]
Good Runtime PM for PCI Device Intel Corporation 100 Series/C230 Series Chipset Family MEI Controller #1
Good Runtime PM for disk sda
Good Runtime PM for PCI Device Intel Corporation 100 Series/C230 Series Chipset Family PCI Express Root Port #9
Good Runtime PM for PCI Device NVIDIA Corporation GM107GLM [Quadro M1200 Mobile]
Good Runtime PM for PCI Device Intel Corporation 100 Series/C230 Series Chipset Family PCI Express Root Port #13
Good Runtime PM for PCI Device Intel Corporation 100 Series/C230 Series Chipset Family PCI Express Root Port #15
Good Runtime PM for PCI Device Intel Corporation 100 Series/C230 Series Chipset Family PCI Express Root Port #2
之前的一个问题（见这里) 在探索风扇的类似问题时提到了 powertop 工具。
答案1
因为 TLP 使用两个根据电源自动应用的设置配置文件：
- 以_AC结尾的参数在AC接通时有效
- 以 _BAT 结尾的参数在使用电池供电时有效
但这当然是可以配置的。
如果您希望交流电的设置与电池模式相同，则可以调整配置（在/etc/tlp.conf） 如下：
TLP_DEFAULT_MODE=BAT
TLP_PERSISTENT_DEFAULT=1
相反，您也可以调整单独的设置，例如 Runtime PM：
RUNTIME_PM_ON_AC=auto
有关详细信息，请参阅文档：