User Manual of DSC Switcher Tool for ThinkPad Universal Thunderbolt 4 Dock
Brand: Lenovo
User Scenario
This section describes different host DSC (Display Stream Compression) states (ON/OFF) and their impact on display connections via the dock.
Host DSC ON
When Host DSC is ON:
- If DSC negotiation state is Off: The dock connects to two monitors, with DSC off for both.
- If DSC negotiation state is On: The dock connects to two monitors, with DSC on for both.
Host DSC OFF
When Host DSC is OFF:
- If DSC negotiation state is Off: The dock connects to two monitors, with DSC off for both.
- If DSC negotiation state is On: The dock connects to two monitors, with DSC off for both.
Lenovo TBT4 Dock Display Connection
To check firmware and DSC status, at least one monitor must be connected to the dock.
- For DP5 DSC status checks, connect a monitor to the DP5-DP Port.
- For DP6 DSC status checks, connect a monitor to the DP6-DP Port or HDMI Port.
The setup involves a Host computer connected via USB Type-C to the Lenovo Thunderbolt 4 Dock. The dock is powered by a Power Adapter and connects to external monitors via Display Port (DP5, DP6) or HDMI.
DSC Switcher Tool UI Introduction
The DSC Switcher Tool interface provides the following information and controls:
- Supported Dock Model with FW Version: Displays the supported dock models and their firmware versions.
- Detected Dock FW Version and Current DP FW: Shows the firmware version detected on the dock and the current DisplayPort firmware version.
- DSC Functionality Status: Indicates whether the current DP firmware supports DSC and the actual DSC status (ON or OFF).
- Disable/Enable FW DSC Button: A button to toggle the DSC function. If DSC is enabled, clicking it disables it, and vice-versa.
Important Notes Before Execution:
- Disabling/Enabling DSC FW may cause firmware update version mismatches.
- The tool requires a monitor to be connected during execution.
- A power cycle of the dock and a system restart are necessary after enabling or disabling FW DSC.
The tool displays the dock's DSC status, which can be ON or OFF. It also shows the DP5 and DP6 firmware versions.
DSC Switcher Tool Log Information
The tool provides log information that:
- Shows detected DP5 & DP6 FW versions and indicates if the current FW DSC function is enabled or disabled.
- Detects the actual DSC function status (ON or OFF) based on monitor connection.
The log output file is named tbt4dk_DSC_Switcher_yyyymmddhhmmss.log.
Tool Execution
This section details the execution of the DSC Switcher Tool, including scenarios for enabling and disabling DSC, and common execution cases.
Disabling FW DSC
The tool can be used to disable the DSC function. After disabling, the DP FW DSC status is shown as Disabled.
Enabling FW DSC
The tool can also be used to enable the DSC function. After enabling, the DP FW DSC status is shown as Enabled.
Execution Cases
This section outlines various scenarios and potential issues encountered during the execution of the DSC Switcher Tool.
Case 1: Find Previous Tool
An error message (❌) indicates that another instance of the tool or "Vmmtool" is already running. The user is prompted to exit the current tool and confirm if another instance is active.
Case 2: Can't Read DP5/DP6 Version
This error (❌) occurs if a monitor is not properly connected to the dock, preventing the tool from reading DP5/DP6 versions. The user is advised to ensure a monitor is connected and retry, or cancel the operation.
Case 3: DP5 & DP6 FW DSC Setting are Mismatched
This case occurs when one DP's DSC setting is enabled while the other is disabled. The tool may prompt the user to continue by updating the firmware to enable both DP5 and DP6 DSC settings, or to cancel.
Case 4: Unsupported Dock Firmware
The tool detects that the connected dock's firmware version is not supported. It specifically supports 40B0 with firmware V1.0.18 and 40B1 with firmware V1.0.07. Users with unsupported firmware (e.g., 40B0 with V1.0.07) must update it before using the tool.
Case 5: DSC FW Setting and DSC Status are Mismatched
⚠️ Warning: DSC FW Setting and DSC Status are mismatched. Please confirm host DSC status is disabled. Continue this tool?
This warning is displayed when the DP DSC Setting is enabled, but the actual DSC Status is OFF. This might be due to host settings. The user can choose to ignore the message and continue disabling FW DSC, or cancel.
Case 6: Detect Current DP FW Version is X.XX.163
❌ Error: Detect DP FW is 163 for PCB 4.0. Not support enable/disable DSC with DP FW 163.
For PCB 4.0, the DP FW version X.XX.163 is supported, but this specific version does not allow enabling or disabling DSC using this tool.
Case 7: DP Load Default FW
❌ Error: DP5 FW is loading default FW. Continue to update all DP FW?
An error occurs when the system is loading the default DP firmware with an unknown issue. The user is given the option to continue updating all DP FW for recovery, with DSC enabled, or to cancel.
Case 8: Please Connect Dock to Host
Error: Please connect dock to host...
The tool cannot detect the connected dock. The user is instructed to connect the dock to the host, after which the tool execution will restart automatically.
Case 9: Execute Completed
✔️ Execute completed! Dock need to do power cycle and then restart the system.
The process to enable or disable FW DSC has been completed successfully. Users are reminded to perform a dock power cycle and restart the system afterwards.
