Windows 11 includes built-in USB Type-C troubleshooting notifications designed to help users identify and resolve issues like slow charging, unsupported accessories, and faulty connections. These notifications are part of a broader effort to improve device reliability and user experience.
While our previous post focused on the user experience, this update is for OEMs highlighting what’s required to ensure these notifications function correctly on your platforms.
Why Notifications Might Not Appear
USB Type-C notifications rely on accurate platform configuration. If notifications aren’t showing up, it’s often due to:
- Missing or incorrect ACPI markup: Windows uses ACPI descriptors to identify USB Type-C ports and their capabilities. If the port isn’t correctly marked as user-accessible or Type-C, notifications may not trigger.
- Incorrect connector type reporting: Mislabeling a Type-A port as Type-C (or vice versa) can lead to unexpected behavior or missed alerts.
- Internal vs. external port confusion: Ports marked as internal may suppress notifications even if they’re physically accessible to users.
Validation and Testing
To ensure compatibility:
- Use the Windows Hardware Lab Kit (HLK) to validate USB port descriptors.
- Confirm that _UPC (USB Port Capabilities) and _PLD (Physical Location of Device) ACPI methods are correctly implemented.
- Test with various charging scenarios, including underpowered chargers and hubs, to verify that notifications appear as expected. The link below has a table of the notifications and expected behaviours.
Security Considerations
Some OEMs may choose to disable data over USB Type-C in untrusted environments. If implementing such features:
- Ensure the policy applies only to externally accessible ports.
- Consider offering user toggles for data disablement.
- Validate that disabling data doesn’t interfere with critical internal devices (e.g., touchpad, keyboard).
Recommendations for OEMs
- Audit ACPI descriptors and USB Device-Specific Method for all USB ports. See https://learn.microsoft.com/en-us/windows-hardware/drivers/bringup/usb-device-specific-method---dsm-#function-7-query-if-_upc-supports-usb-c-port-capabilities-as-defined-in-acpi-specification-65
- Validate notification behavior across all supported configurations.
- Coordinate with Microsoft WHCP to ensure new platforms meet testing requirements.
- Document exceptions clearly if certain ports or configurations are unsupported.
Learn More
For technical details and troubleshooting guidance, refer to the official documentation:
https://learn.microsoft.com/windows-hardware/drivers/usbcon/usb-type-c-troubleshooting-notifications