Windows 11/10 已经获得了很多有用的功能。这些发布的功能既基于消费者，也基于开发者。除此之外，他们也没有错过即兴发挥旧功能。其中一项功能是USB 选择性挂起功能。(USB Selective Suspend feature.)
什么是Windows中的(Windows)USB 选择性挂起(USB Selective Suspend)功能？
在Windows 操作系统(Windows OS)中，选择性挂起(Selective Suspend)功能允许系统通过将某些USB端口置于挂起模式来节省电量。它允许集线器驱动程序挂起单个端口，但不影响其他端口的功能。例如，它类似于用户将笔记本电脑或其他设备置于睡眠模式的方式——选择性挂起(Sleep Mode – Selective Suspend)几乎就是这样。让它如此有趣的功能是它可以单独挂起特定的USB端口，而不会影响整个USB端口的电源。但是，USB设备的驱动程序必须支持选择性挂起(Selective Suspend)才能正常运行。
USB 核心堆栈支持(USB Core Stack)通用串行总线规范(Universal Serial Bus Specification)的修改版本，称为“选择性挂起”。这允许集线器驱动程序(Hub Driver)暂停端口并帮助节省电池。暂停指纹读取器(Fingerprint Reader)等服务，这些服务并非一直都需要，有助于降低功耗。此功能的行为对于在Windows XP中运行的设备有所不同，并在(Windows XP)Windows Vista和更高版本中不断改进。
用户在已经在充电并且可以在需要时使用插入式电源的系统上并不真正需要它。这就是为什么Windows允许用户根据计算机的插件或电池启用USB 选择性挂起。(USB Selective Suspend)但是选择性挂起(Selective Suspend)功能并不是插入电源的台式机的要求。当USB端口断电时，它不一定会在桌面上节省那么多电量。这就是为什么Windows允许您根据插入的计算机或电池电源启用或禁用USB 选择性挂起。(USB Selective Suspend)此功能对于便携式计算机的省电目的非常有用。
如何启用或禁用USB 选择性挂起(USB Selective Suspend)
一些用户报告说，在应用选择性挂起后，有时(Selective Suspend)USB端口不会重新打开。有时甚至会在没有警告的情况下自行关闭。要解决此问题，您需要禁用系统上的USB 选择性挂起(USB Selective Suspend)功能。以下是您的操作方法：
相关(Related)：USB 挂起：USB 设备未进入选择性挂起
通过电源选项
打开Windows PC 上的控制面板。(Control Panel)为此，请在搜索框中搜索控制面板 (Control Panel )。
现在，导航到此路径：Control Panel > Hardware和Sound > Power Options。
单击(Click)您选择的电源计划(Power Plan)，然后单击 更改计划设置(Change Plan Settings)。
这将带您进入一个新页面，您需要单击 更改高级电源设置。(Change advanced power settings.)
现在将出现一个新的更详细的高级电源选项(Advanced power options)框。将有一个菜单显示 USB 设置(USB Settings)。
展开该选项，您将在那里找到两个子选项，分别标记为 On Battery 和 On Power。
您可以根据自己的选择分别启用它们。
单击 确定(OK)以进行更改。
相关(Related)：选择性挂起会导致 USB 集线器上的 USB 设备停止运行。
使用 Windows 注册表
要通过注册表编辑器(Registry Editor)禁用选择性挂起(Selective Suspend)功能，请执行以下操作：
由于这是注册表操作，建议您备份注册表(back up the registry) 或 创建系统还原点作为必要的预防措施。完成后，您可以执行以下操作：
- 按Windows key + R调用“运行”对话框。
- 在“运行”对话框中，键入regedit并按 Enter 以打开注册表编辑器(open Registry Editor)。
- 导航或跳转到下面的注册表项路径：
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USB
如果 USB 密钥不存在，您可以右键单击左侧导航窗格中的 Services子父文件夹，单击新建(New) > 密钥(Key) 以 创建注册表项 ，然后将密钥重命名为 USB 并按 Enter。
- 在该位置的右窗格中，双击DisableSelectiveSuspend 条目以编辑其属性。
如果该键不存在，请右键单击右侧窗格中的空白区域，然后选择新建(New)> DWORD（32 位）值(DWORD (32-bit) Value) 以创建注册表项，然后将该键重命名为DisableSelectiveSuspend 并按 Enter。
- 现在，双击新条目以编辑其属性。
- 在值(V)数据(alue data)字段中输入1 。
- 单击确定(OK)或按 Enter 保存更改。
- 退出注册表编辑器。
- 重新启动您的电脑。
在我们的下一篇文章中，我们将了解如果禁用 USB 选择性挂起您可以做什么。
What is USB Selective Suspend feature? How to enable or disable it?
Windows 11/10 has been getting a lot of useful features. These features released are both consumer-bаsed and developer-based. Along with this, they haνe nоt missed improvising the old features. One of thеse features is USB Selective Suspend feature.
What is USB Selective Suspend feature in Windows?
In Windows OS, the Selective Suspend feature allows the system to save power by putting certain USB ports into a suspended mode. It lets the hub driver suspend a single port but does not affect the functioning of other ports. For instance, it’s similar to how users put their laptops or other devices in Sleep Mode – Selective Suspend is almost like that. The feature which makes it so interesting is that it can suspend a specific USB port individually, without affecting the power of the entire USB port. However, the driver for the USB device must support Selective Suspend for it to run right.
The USB Core Stack supports a modified revision of the Universal Serial Bus Specification and is called ‘selective suspend’. This allows the Hub Driver to suspend a port and help conserve the battery. Suspending services like Fingerprint Reader, etc., which are not required all the time, helps improve power consumption. The behavior of this feature is different for devices operating in Windows XP and kept improving in Windows Vista and later versions.
Users don’t really need this on a system that is already charging and can avail of the plug-in power whenever it needs to. This is why Windows lets users enable the USB Selective Suspend based on the computer’s plug-in or battery. But the Selective Suspend feature isn’t exactly a requirement on a desktop machine that is plugged into power. When a USB port is powered down, it doesn’t necessarily save that much of power on a desktop. That’s why Windows allows you to enable or disable USB Selective Suspend based on the computer being plugged in or on battery power. This feature is incredibly helpful in portable computers for power-saving purposes.
How to enable or disable USB Selective Suspend
Some users have reported that at times the USB port does not get turned back on after Selective Suspend has been applied. Or sometimes even turns itself off without warning. To fix this, you need to disable the USB Selective Suspend feature on your system. Here’s how you can do it:
Related: USB Suspend:USB Device not Entering Selective Suspend
Via Power Options
Open Control Panel on your Windows PC. To do this, search for Control Panel in the search box.
Now, navigate to this path: Control Panel > Hardware and Sound > Power Options.
Click on your selected Power Plan, then click on Change Plan Settings.
This will take you to a new page where you will need to click on Change advanced power settings.
Now a new and more detailed box of Advanced power options will appear. There will be a menu that says USB Settings.
Expand that option, and you will find two sub-options there that will be labeled as On Battery and On Power.
You can choose to enable both of them individually as per your choice.
Click on OK for the change to take place.
Related: Selective Suspend causes USB devices on USB hub to stop functioning.
Using Windows Registry
To disable the Selective Suspend feature via the Registry Editor, do the following:
Since this is a registry operation, it is recommended that you back up the registry or create a system restore point as necessary precautionary measures. Once done, you can proceed as follows:
- Press Windows key + R to invoke the Run dialog.
- In the Run dialog box, type regedit and hit Enter to open Registry Editor.
- Navigate or jump to the registry key path below:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USB
If the USB key is not present, you can right-click on the Services sub-parent folder on the left navigation pane, click New > Key to create the registry key and then rename the key as USB and hit Enter.
- At the location, on the right pane, double-click the DisableSelectiveSuspend entry to edit its properties.
If the key is not present, right-click on the blank space on the right pane and then select New > DWORD (32-bit) Value to create the registry key and then rename the key as DisableSelectiveSuspend and hit Enter.
- Now, double-click on the new entry to edit its properties.
- Input 1 in the Value data field.
- Click OK or hit Enter to save the change.
- Exit Registry Editor.
- Restart your PC.
In our next post, we will see what you can do if the USB Selective Suspend is disabled.
